FCEUX - FCEUX is a Nintendo Entertainment System (NES), Famicom, and Famicom Disk System (FDS) emulator.
Project64 - Project64 is a Nintendo 64 emulator for the Windows platform.
Nestopia - A portable and cycle-accurate NES emulator written in C++
Mupen64Plus - N64 emulator and plugins for Linux, Mac OSX, FreeBSD, and Windows
RetroArch - RetroArch is a frontend for emulators, game engines and media players.
VirtuaNES - VirtuaNES is Famicom/NES emulator for Win32.