re: I need an affordable gaming PC.

Why not 8.1 with classic shell start menu? It's practically identical in interface, but 8.1 is a bit leaner and has a few extra security enhancements under the hood.

There's no right answer though, to say you should or shouldn't stick with Windows 7. If purchasing either, and they are the same price, I'd just get 8.1. If you already have 7, stick with 7. If you can get 7 cheaper (assuming you aren't pirating), get 7.