RetroArch - RetroArch is a frontend for emulators, game engines and media players.
Mupen64Plus - N64 emulator and plugins for Linux, Mac OSX, FreeBSD, and Windows
mGBA - mGBA is an open source emulator of the Game Boy Advance. The goals are speed and accuracy.
1964 - 1964 is a Nintendo 64 emulator for Microsoft Windows, written in C and released as free software.
DeSmuME - DeSmuME is a freeware emulator for the NDS roms & Nintendo DS Lite games created by YopYop156.
Corn - Corn is a very fast Nintendo 64 emulator.