RetroArch - RetroArch is a frontend for emulators, game engines and media players.
Mesen - Mesen is a NES/Famicom emulator and NSF player.
Mupen64Plus - N64 emulator and plugins for Linux, Mac OSX, FreeBSD, and Windows
Snes9x - Snes9x is a portable, Super Nintendo Entertainment System (SNES) emulator.
1964 - 1964 is a Nintendo 64 emulator for Microsoft Windows, written in C and released as free software.
BSNES - bsnes is a Super Nintendo (SNES) emulator focused on performance, features, and ease of use.