Super Nintendo Entertainment System
The ZSNES is the Dos version of the Snes emulator, very good plays almost all games. Has sound and cheat functions, also has high quality screen resolution.
Nintendo Entertainment System
By far I think the best NES emulator around, plays almost all games all you'll ever need for NES games.
Super Gameboy Color
I think this is the best gameboy emulator by far it is able to play all gameboy types and all gameboy games, it also plays NES games aswell. More than you would ever expect from a emulator.