Nestopia is by far the most compatible of any NES emulator for Mac OS X.
Nestopia is a Nintendo NES emulator for Mac OS X. The best part of the emulator is that, in most cases (or at least if your computer is relatively new), the graphics will be even better than they are on the original consoles. With it, you can play virtually any game from the Nintendo catalog with no problems.
Dolphin is the best emulator for Nintendo Wii and Gamecube currently available.
