Computer Construction Enthusiasts

[Magus]

What I've got:

RAM (I got 16 GB, I think that's enough?)
Power Supply
Case
SSD and HDD

What I still need
Operating System (Windows 8, I guess?)
Mobo
CPU (looking at a few)
Graphics Card
Sound Card

16GB RAM is overkill if you're just building a gaming rig. You will never need more than 8 even running everything maxed out (this will likely change in whatever generation comes after PS4/XB1 but you've got some time for that).

Win8 isn't as bad as everyone says but 7 is better. Consider pirating 7 and upgrading to 10 for free. Not that I'd know anything about that.

For the GPU, the R9 series is pretty great if you want a seriously good card on a budget. They don't run very hot either, contrary to popular opinion. I have a Sapphire R9 290 (4GB DDR5) and it has never seen high temps. A lot of GPUs have built-in audio support, too! Might save you a PCI slot (and some cash).

Don't skimp on the mobo, either. Especially if you want to overclock. You can get an Asus for a reasonable price if you're on a budget and if you want to go all-out you can get a badass ASRock one or something.

I'd be happy to nerd out about the various bits and bobs w/ you if you ever want.