What kind of laptop should I be using: Alienware or Macbook Pro?
If you plan on using Premiere, Adobe recommends 16GB of RAM and a minimum of 8GB. They minimum RAM for After Effects is less, but there are some other equally important things to consider. I'd also recommend spending as much as you can on as much SSD storage as you can afford.

Check the specs of the software you want to use for editing - particularly the minimum RAM and the kind of Graphics processor (GPU). If you want to use DaVinci Resolve for editing (it is FREE) and color correcting - you'll want all the RAM you can get.

If you are comfortable with the hardware, I'd recommend a Dell or HP laptop as you will likely find more affordable options for RAM, GPU and SSD than what Apple offers. I don't know much about gaming, but I understand Windows solutions are what the kids dig. FWIW I am plugging along on an 11" mid-2012 i7 AirBook and it does alright with an external monitor out the Thunderport. I edit with Resolve, iMovie, &amp; LightWorks and move pixels about with ffmpeg. Nothing fancy or long-form, but I'd much prefer a 15" screen.