Project64 - Project64 is a Nintendo 64 emulator for the Windows platform.
RetroArch - RetroArch is a frontend for emulators, game engines and media players.
Mupen64Plus - N64 emulator and plugins for Linux, Mac OSX, FreeBSD, and Windows
Mesen - Mesen is a NES/Famicom emulator and NSF player.
Snes9x - Snes9x is a portable, Super Nintendo Entertainment System (SNES) emulator.
Corn - Corn is a very fast Nintendo 64 emulator.