FCEUX - FCEUX is a Nintendo Entertainment System (NES), Famicom, and Famicom Disk System (FDS) emulator.
RetroArch - RetroArch is a frontend for emulators, game engines and media players.
Nestopia - A portable and cycle-accurate NES emulator written in C++
Mednafen - Mednafen is a portable, utilizing OpenGL and SDL, argument(command-line)-driven multi-system...
OpenEmu - Console and Arcade video game emulator for macOS.
VirtuaNES - VirtuaNES is Famicom/NES emulator for Win32.