7 and 8 runs natively in windows, cracked versions can be a bother, be sure to patch the games or you might end up getting stuck due to bugggage.
you can pirate all the playstation, nintendo, and gameboy releases and emulate them, ps2 emulation can be a bit tricky, but if you have the patience to tweak your emulator, you can play all the ps2 releases too.
i suggest getting a xbox 360 wireless controller if you're going to emulate, it works with a lot of pc games too, and can be set up to be a secondary mouse or remote control for media players.