Ares

Ares is an open source, multi-system emulator that lets you play classic games on more than 20 different consoles, including Wonderswan and Wonderswan Color, Coleco Vision, MSX and MSX 2, Nintendo NES and SNES, Gameboy Color and Gameboy Advance, Sega Mega Drive and Mega CD, Neo Geo Pocket and Neo Geo Pocket Color, Sony Playstation, and others.

From the options menu, you can set up all the emulators and manually add the necessary BIOS. Keep in mind that this program doesn't include any BIOS itself. To get the BIOS, it's best to export the files directly from your own console or search for them online.

From the settings menu, you can customize the controls you use for each platform. Ares automatically recognizes if you have an Xbox gamepad connected, but you can also connect other kinds of controllers or simply use your keyboard. For some of the consoles, using your keyboard is actually the most comfortable option.

Ares is an excellent multi-system emulator that includes a great variety of consoles, and all from an elegant, simple, and easy-to-use interface. Even better, the program is lightweight and doesn't require installation. All you have to do is find its folder, unzip the file, and start emulating the consoles you're interested in.