What are the differences (and value adds) among all the different Crypto Currencies? This website lists hundreds of crypto currencies. Some whimsical, others with a unique value.

Is there a catalog, or diff between all the implementations that highlights innovation, or a unique use case? 

My goal is to prioritize which implementations to learn the most (BTC, ETH, and Ripple with the most market cap is my first priority)
99% of altcoins claim an "innovation" that is broken or unproven.

I would say that the first thing to do is look at unique codebases that aren't based on Bitcoin, which basically means (besides Bitcoin) you should look at Ethereum, Ripple, NXT, Monero, BitShares. Then if you're bored, PeerCoin / NuBits and Lisk.

Once you are done with those you can look at altcoins that just clone Bitcoin, but if they don't have whitepapers with cryptography that explains what they're doing then they're just full of hot air.