RetroArch - RetroArch is a frontend for emulators, game engines and media players.
Wine - Open Source Software for running Windows applications on other operating systems.
Mesen - Mesen is a NES/Famicom emulator and NSF player.
CodeWeavers CrossOver - Don't buy a Windows license, don't reboot and don't use a Virtual Machine. Try a free trial of CrossOver to run your Windows software on Mac, Linux and Chrome OS.
Snes9x - Snes9x is a portable, Super Nintendo Entertainment System (SNES) emulator.
PlayOnLinux - PlayOnLinux will allow you to play your favorite games on Linux easily