user1908: It's that time of the quarter again: the fall season of anime is starting. We want to get as many tags as possible for this season's shows into the system, both so we get more interesting content on the site and so that low-rep users don't have to bumble their way into the retag workaround. 
If you're looking for something to watch this season, consider picking something from the list below. Who knows, it might prompt you to ask some interesting questions!
(Previous editions: summer 2015, spring 2015, and more.)

user1908: Please keep this answer voted below the other one, so the other one is more visible.
I would like to set some targets for which tags we should try to have in the system by the time the season ends (at the end of December). Getting all of the currently unasked-about series in the system obviously isn't going to happen, since a lot of those series are e.g. family-oriented shows that nobody outside Japan watches. 
Instead, I propose that we should try to focus on shows that are likely to have a reasonably-sized English-speaking viewer base. In my estimation, that means the following shows (that don't already have tags; bold for particularly "important" ones):

Comet Lucifer
Concrete Revolutio
Dance with Devils
Gakusen Toshi Asterisk
Hacka Doll (a short, but by Trigger)
Heavy Object (going to be super-popular because Kamachi)
Hidan no Aria (this somehow got a sequel, so clearly somebody is still into the KugiRie-as-tsundere genre)
Rakudai Kishi no Eiyuutan
Sakurako-san
Shinmai Maou no Testament
Shomin Sample
Subete ga F ni Naru (lots of hype here)
Taimadou Gakuen 35 etc

I will probably watch most of these and ask questions about them as I have them. If you're watching any of these shows, you might like to try to do the same.

In summary: by the end of the fall 2015 season (plus a few days), we managed to get questions about 7/13 of the shows listed above. Not bad, though I have to think we could've done better. (I, personally, also watched Dance with Devils, but was unable to muster any interesting questions about it.)
Oh, well. On to winter 2016!

user1908: Note that shows for which we have tags are struckthrough. Additionally, shows for which we had tags at the beginning of the season are unbolded.
New full-length shows

Brave Beats
Comet Lucifer comet-lucifer
Concrete Revolutio: Choujin Gensou
Dance with Devils
Gakusen Toshi Asterisk gakuen-toshi-asterisk
Heavy Object heavy-object
Kamisama Minarai: Himitsu no Cocotama (use himitsu-no-cocotama)
Lance N' Masques
One Punch Man one-punch-man
Ore ga Ojou-sama Gakkou ni "Shomin Sample" toshite Gets-sareta Ken (use shomin-sample)
Rakudai Kishi no Eiyuutan rakudai-kishi-no-cavalry
Sakurako-san no Ashimoto ni wa Shitai ga Umatteiru sakurako-san
Star Mu, aka High School Star Musical
Subete ga F ni Naru: The Perfect Insider subete-ga-f-ni-naru
Taimadou Gakuen 35 Shiken Shoutai (use 35-shoutai)
Valkyrie Drive: Mermaid

Full-length sequels

Aikatsu aikatsu
Cardfight!! Vanguard G: Gears Crisis-hen cardfight-vanguard
Garo: Guren no Tsuki garo
Gochuumon wa Usagi Desu ka?? is-the-order-a-rabbit
Haikyuu!! 2 haikyuu
Hidan no Aria
K: Return of Kings k-project
Kidou Senshi Gundam: Tekketsu no Orphans gundam (or, if you prefer, create a new tag gundam-g-tekketsu)
Kindaichi Shounen no Jikenbo R 2 (use kindaichi-shounen)
Noragami Aragoto noragami
Osomatsu-san
Owari no Seraph: Nagoya Kessen-hen owari-no-seraph (cour 2 of a split-cour)
Owarimonogatari monogatari-series
Peeping Life TV: Season 1??
Pokemon XY & Z pokemon
Shin Atashin'chi
Shingeki! Kyojin Chuugakkou shingeki-no-kyojin
Shinmai Maou no Testament Burst
Soukyuu no Fafner: Exodus 2
Utawarerumono: Itsuwari no Kamen utawarerumono
World Trigger: Isekai kara no Toubousha world-trigger
Young Black Jack black-jack
Yuru Yuri San☆Hai yuru-yuri

Shorts

Ameiro Cocoa: Rainy Color e Youkoso!
Anitore! EX
Diabolik Lovers More,Blood diabolik-lovers
Doushite mo Eto ni Hairitai
Fushigi na Somera-chan
Fuusen Inu Tinny 2nd Season
Hacka Doll: The Animation hacka-doll
Hokuto no Ken: Ichigo Aji hokuto-no-ken
Itoshi no Muco
JK-Meshi
Kagewani
Ketsuekigata-kun! 3
Komori-san wa Kotowarenai
Kowabon kowabon
Kyoufu! Zombie Neko
Mini Vanguard 2
Miss Monochrome: The Animation 3 miss-monochrome
Neko no Dayan: Nihon e Iku
Onsen no Yousei Hakone-chan
Tantei Team KZ Jiken Note
Teekyuu 6 teekyuu

Leftovers from previous seasons

Aquarion Logos aquarion
Lupin III: L'avventura Italiana lupin-the-third
Ushio to Tora ushio-to-tora

(and probably some others I missed)
Movies coming out on BD this season

Sarusuberi: Miss Hokusai


Listings culled from Anichart, Senpai.moe, and The Cart Driver.

1908: <p>It's that time of the quarter again: the fall season of anime is starting. We want to get as many tags as possible for this season's shows into the system, both so we get more interesting content on the site and so that low-rep users don't have to bumble their way into the <a href="https://anime.stackexchange.com/questions/tagged/retag" class="post-tag" title="show questions tagged &#39;retag&#39;" rel="tag">retag</a> workaround. </p>

<p>If you're looking for something to watch this season, consider picking something from the list below. Who knows, it might prompt you to ask some interesting questions!</p>

<p>(Previous editions: <a href="https://anime.meta.stackexchange.com/questions/2455/">summer 2015</a>, <a href="https://anime.meta.stackexchange.com/q/2303/">spring 2015</a>, <a href="https://anime.meta.stackexchange.com/questions/tagged/tags-by-season">and more</a>.)</p>
 1908: <p>Please keep this answer voted below <a href="https://anime.meta.stackexchange.com/a/2635/">the other one</a>, so the other one is more visible.</p>

<p>I would like to set some targets for which tags we should try to have in the system by the time the season ends (at the end of December). Getting <em>all</em> of the currently unasked-about series in the system obviously isn't going to happen, since a lot of those series are e.g. family-oriented shows that nobody outside Japan watches. </p>

<p>Instead, I propose that we should try to focus on shows that are likely to have a reasonably-sized English-speaking viewer base. In my estimation, that means the following shows (that don't already have tags; bold for particularly "important" ones):</p>

<ul>
<li><s>Comet Lucifer</s></li>
<li>Concrete Revolutio</li>
<li>Dance with Devils</li>
<li><s>Gakusen Toshi Asterisk</s></li>
<li><s>Hacka Doll</s> (a short, but by Trigger)</li>
<li><s><strong>Heavy Object</strong></s> (going to be super-popular because Kamachi)</li>
<li>Hidan no Aria (this somehow got a sequel, so clearly somebody is still into the KugiRie-as-tsundere genre)</li>
<li><s>Rakudai Kishi no Eiyuutan</s></li>
<li><s>Sakurako-san</s></li>
<li>Shinmai Maou no Testament</li>
<li>Shomin Sample</li>
<li><s><strong>Subete ga F ni Naru</strong></s> (lots of hype here)</li>
<li>Taimadou Gakuen 35 etc</li>
</ul>

<p>I will probably watch most of these and ask questions about them as I have them. If you're watching any of these shows, you might like to try to do the same.</p>

<hr>

<p>In summary: by the end of the fall 2015 season (plus a few days), we managed to get questions about 7/13 of the shows listed above. Not bad, though I have to think we could've done better. (I, personally, also watched Dance with Devils, but was unable to muster any interesting questions about it.)</p>

<p>Oh, well. On to winter 2016!</p>
 1908: <p>Note that shows for which we have tags are <s>struckthrough</s>. Additionally, shows for which we had tags <em>at the beginning of the season</em> are unbolded.</p>

<h1>New full-length shows</h1>

<ul>
<li><strong>Brave Beats</strong></li>
<li><s><strong>Comet Lucifer</strong></s> <a href="https://anime.stackexchange.com/questions/tagged/comet-lucifer" class="post-tag" title="show questions tagged &#39;comet-lucifer&#39;" rel="tag">comet-lucifer</a></li>
<li><strong>Concrete Revolutio: Choujin Gensou</strong></li>
<li><strong>Dance with Devils</strong></li>
<li><s><strong>Gakusen Toshi Asterisk</strong></s> <a href="https://anime.stackexchange.com/questions/tagged/gakuen-toshi-asterisk" class="post-tag" title="show questions tagged &#39;gakuen-toshi-asterisk&#39;" rel="tag">gakuen-toshi-asterisk</a></li>
<li><s><strong>Heavy Object</strong></s> <a href="https://anime.stackexchange.com/questions/tagged/heavy-object" class="post-tag" title="show questions tagged &#39;heavy-object&#39;" rel="tag">heavy-object</a></li>
<li><strong>Kamisama Minarai: Himitsu no Cocotama</strong> (use <em>himitsu-no-cocotama</em>)</li>
<li><strong>Lance N' Masques</strong></li>
<li><s>One Punch Man</s> <a href="https://anime.stackexchange.com/questions/tagged/one-punch-man" class="post-tag" title="show questions tagged &#39;one-punch-man&#39;" rel="tag">one-punch-man</a></li>
<li><strong>Ore ga Ojou-sama Gakkou ni "Shomin Sample" toshite Gets-sareta Ken</strong> (use <em>shomin-sample</em>)</li>
<li><s><strong>Rakudai Kishi no Eiyuutan</strong></s> <a href="https://anime.stackexchange.com/questions/tagged/rakudai-kishi-no-cavalry" class="post-tag" title="show questions tagged &#39;rakudai-kishi-no-cavalry&#39;" rel="tag">rakudai-kishi-no-cavalry</a></li>
<li><s><strong>Sakurako-san no Ashimoto ni wa Shitai ga Umatteiru</strong></s> <a href="https://anime.stackexchange.com/questions/tagged/sakurako-san" class="post-tag" title="show questions tagged &#39;sakurako-san&#39;" rel="tag">sakurako-san</a></li>
<li><strong>Star Mu</strong>, aka <strong>High School Star Musical</strong></li>
<li><s><strong>Subete ga F ni Naru: The Perfect Insider</strong></s> <a href="https://anime.stackexchange.com/questions/tagged/subete-ga-f-ni-naru" class="post-tag" title="show questions tagged &#39;subete-ga-f-ni-naru&#39;" rel="tag">subete-ga-f-ni-naru</a></li>
<li><strong>Taimadou Gakuen 35 Shiken Shoutai</strong> (use <em>35-shoutai</em>)</li>
<li><strong>Valkyrie Drive: Mermaid</strong></li>
</ul>

<h1>Full-length sequels</h1>

<ul>
<li><s>Aikatsu</s> <a href="https://anime.stackexchange.com/questions/tagged/aikatsu" class="post-tag" title="show questions tagged &#39;aikatsu&#39;" rel="tag">aikatsu</a></li>
<li><s>Cardfight!! Vanguard G: Gears Crisis-hen</s> <a href="https://anime.stackexchange.com/questions/tagged/cardfight-vanguard" class="post-tag" title="show questions tagged &#39;cardfight-vanguard&#39;" rel="tag">cardfight-vanguard</a></li>
<li><s>Garo: Guren no Tsuki</s> <a href="https://anime.stackexchange.com/questions/tagged/garo" class="post-tag" title="show questions tagged &#39;garo&#39;" rel="tag">garo</a></li>
<li><s>Gochuumon wa Usagi Desu ka??</s> <a href="https://anime.stackexchange.com/questions/tagged/is-the-order-a-rabbit" class="post-tag" title="show questions tagged &#39;is-the-order-a-rabbit&#39;" rel="tag">is-the-order-a-rabbit</a></li>
<li><s>Haikyuu!! 2</s> <a href="https://anime.stackexchange.com/questions/tagged/haikyuu" class="post-tag" title="show questions tagged &#39;haikyuu&#39;" rel="tag">haikyuu</a></li>
<li><strong>Hidan no Aria</strong></li>
<li><s>K: Return of Kings</s> <a href="https://anime.stackexchange.com/questions/tagged/k-project" class="post-tag" title="show questions tagged &#39;k-project&#39;" rel="tag">k-project</a></li>
<li><s>Kidou Senshi Gundam: Tekketsu no Orphans</s> <a href="https://anime.stackexchange.com/questions/tagged/gundam" class="post-tag" title="show questions tagged &#39;gundam&#39;" rel="tag">gundam</a> (or, if you prefer, create a new tag <em>gundam-g-tekketsu</em>)</li>
<li><strong>Kindaichi Shounen no Jikenbo R 2</strong> (use <em>kindaichi-shounen</em>)</li>
<li><s>Noragami Aragoto</s> <a href="https://anime.stackexchange.com/questions/tagged/noragami" class="post-tag" title="show questions tagged &#39;noragami&#39;" rel="tag">noragami</a></li>
<li><strong>Osomatsu-san</strong></li>
<li><s>Owari no Seraph: Nagoya Kessen-hen</s> <a href="https://anime.stackexchange.com/questions/tagged/owari-no-seraph" class="post-tag" title="show questions tagged &#39;owari-no-seraph&#39;" rel="tag">owari-no-seraph</a> (cour 2 of a split-cour)</li>
<li><s>Owarimonogatari</s> <a href="https://anime.stackexchange.com/questions/tagged/monogatari-series" class="post-tag" title="show questions tagged &#39;monogatari-series&#39;" rel="tag">monogatari-series</a></li>
<li><strong>Peeping Life TV: Season 1??</strong></li>
<li><s>Pokemon XY &amp; Z</s> <a href="https://anime.stackexchange.com/questions/tagged/pokemon" class="post-tag" title="show questions tagged &#39;pokemon&#39;" rel="tag">pokemon</a></li>
<li><strong>Shin Atashin'chi</strong></li>
<li><s>Shingeki! Kyojin Chuugakkou</s> <a href="https://anime.stackexchange.com/questions/tagged/shingeki-no-kyojin" class="post-tag" title="show questions tagged &#39;shingeki-no-kyojin&#39;" rel="tag">shingeki-no-kyojin</a></li>
<li><strong>Shinmai Maou no Testament Burst</strong></li>
<li><strong>Soukyuu no Fafner: Exodus 2</strong></li>
<li><s>Utawarerumono: Itsuwari no Kamen</s> <a href="https://anime.stackexchange.com/questions/tagged/utawarerumono" class="post-tag" title="show questions tagged &#39;utawarerumono&#39;" rel="tag">utawarerumono</a></li>
<li><s>World Trigger: Isekai kara no Toubousha</s> <a href="https://anime.stackexchange.com/questions/tagged/world-trigger" class="post-tag" title="show questions tagged &#39;world-trigger&#39;" rel="tag">world-trigger</a></li>
<li><s>Young Black Jack</s> <a href="https://anime.stackexchange.com/questions/tagged/black-jack" class="post-tag" title="show questions tagged &#39;black-jack&#39;" rel="tag">black-jack</a></li>
<li><s>Yuru Yuri San☆Hai</s> <a href="https://anime.stackexchange.com/questions/tagged/yuru-yuri" class="post-tag" title="show questions tagged &#39;yuru-yuri&#39;" rel="tag">yuru-yuri</a></li>
</ul>

<h1>Shorts</h1>

<ul>
<li><strong>Ameiro Cocoa: Rainy Color e Youkoso!</strong></li>
<li><strong>Anitore! EX</strong></li>
<li><s>Diabolik Lovers More,Blood</s> <a href="https://anime.stackexchange.com/questions/tagged/diabolik-lovers" class="post-tag" title="show questions tagged &#39;diabolik-lovers&#39;" rel="tag">diabolik-lovers</a></li>
<li><strong>Doushite mo Eto ni Hairitai</strong></li>
<li><strong>Fushigi na Somera-chan</strong></li>
<li><strong>Fuusen Inu Tinny 2nd Season</strong></li>
<li><s><strong>Hacka Doll: The Animation</strong></s> <a href="https://anime.stackexchange.com/questions/tagged/hacka-doll" class="post-tag" title="show questions tagged &#39;hacka-doll&#39;" rel="tag">hacka-doll</a></li>
<li><s>Hokuto no Ken: Ichigo Aji</s> <a href="https://anime.stackexchange.com/questions/tagged/hokuto-no-ken" class="post-tag" title="show questions tagged &#39;hokuto-no-ken&#39;" rel="tag">hokuto-no-ken</a></li>
<li><strong>Itoshi no Muco</strong></li>
<li><strong>JK-Meshi</strong></li>
<li><strong>Kagewani</strong></li>
<li><strong>Ketsuekigata-kun! 3</strong></li>
<li><strong>Komori-san wa Kotowarenai</strong></li>
<li><s><strong>Kowabon</strong></s> <a href="https://anime.stackexchange.com/questions/tagged/kowabon" class="post-tag" title="show questions tagged &#39;kowabon&#39;" rel="tag">kowabon</a></li>
<li><strong>Kyoufu! Zombie Neko</strong></li>
<li><strong>Mini Vanguard 2</strong></li>
<li><s>Miss Monochrome: The Animation 3</s> <a href="https://anime.stackexchange.com/questions/tagged/miss-monochrome" class="post-tag" title="show questions tagged &#39;miss-monochrome&#39;" rel="tag">miss-monochrome</a></li>
<li><strong>Neko no Dayan: Nihon e Iku</strong></li>
<li><strong>Onsen no Yousei Hakone-chan</strong></li>
<li><strong>Tantei Team KZ Jiken Note</strong></li>
<li><s>Teekyuu 6</s> <a href="https://anime.stackexchange.com/questions/tagged/teekyuu" class="post-tag" title="show questions tagged &#39;teekyuu&#39;" rel="tag">teekyuu</a></li>
</ul>

<h1>Leftovers from previous seasons</h1>

<ul>
<li><s>Aquarion Logos</s> <a href="https://anime.stackexchange.com/questions/tagged/aquarion" class="post-tag" title="show questions tagged &#39;aquarion&#39;" rel="tag">aquarion</a></li>
<li><s>Lupin III: L'avventura Italiana</s> <a href="https://anime.stackexchange.com/questions/tagged/lupin-the-third" class="post-tag" title="show questions tagged &#39;lupin-the-third&#39;" rel="tag">lupin-the-third</a></li>
<li><s>Ushio to Tora</s> <a href="https://anime.stackexchange.com/questions/tagged/ushio-to-tora" class="post-tag" title="show questions tagged &#39;ushio-to-tora&#39;" rel="tag">ushio-to-tora</a></li>
</ul>

<p>(and probably some others I missed)</p>

<h1>Movies coming out on BD this season</h1>

<ul>
<li><strong>Sarusuberi: Miss Hokusai</strong></li>
</ul>

<hr>

<p>Listings culled from <a href="http://anichart.net/fall" rel="nofollow noreferrer">Anichart</a>, <a href="http://www.senpai.moe/?season=fall2015&amp;sort=premiere&amp;mode=table" rel="nofollow noreferrer">Senpai.moe</a>, and <a href="http://thecartdriver.com/fall-2015-anime-season-preview/" rel="nofollow noreferrer">The Cart Driver</a>.</p>
