RetroArch - RetroArch is a frontend for emulators, game engines and media players.
Citra - Citra is a work-in-progress emulator for the Nintendo 3DS.
Snes9x - Snes9x is a portable, Super Nintendo Entertainment System (SNES) emulator.
TronDS - A Nintendo 3DS Emulator, It's very simple and is only capable of running homebrews.
BSNES - bsnes is a Super Nintendo (SNES) emulator focused on performance, features, and ease of use.
CD-i Emulator - The CD-i emulator program (cdiemu) provides a fairly complete emulation of the hardware of an actual physical CD-i player.