GPemu - GPemu is a Chrome Extension that serves as a video game emulator designed to play ROMs of various gaming consoles, including Gameboy Advance, NES, Gameboy, and SNES.
Mesen - Mesen is a NES/Famicom emulator and NSF player.
VisualBoyAdvance - VisualBoyAdvance (VBA) is a free software (GNU GPL) emulator targeted for the Game Boy, Super Game...
Nestopia - A portable and cycle-accurate NES emulator written in C++
DeSmuME - DeSmuME is a freeware emulator for the NDS roms & Nintendo DS Lite games created by YopYop156.
puNES - PuNES is a high accuracy NES emulator.