Ultrahle- It works, but requires a Pentium 266 and a very good video card.

Genecyst- Works great as far as I know.

Zsnes- Great SNES emulator. I use it all the time.

NESticle- Works for almost all Nintendo games.

NoGMB- Works great as far as I know.

Virtual Gameboy- Another Gameboy emulator that will play most all gameboy games.

Stella- Works great as far as I know.