Here is a the list of available modules , it covers about 45 kind of machines. (some module being multi-machine)
3DO
Amiga
AmstradCPC
Arcade Simple
Arcade Enhanced
Atari 2600
Atari ST
Commodore 64
Dreamcast
Flash games
Game Boys
Genesis/Megadrive
Intellivision
Jaguar
LazerDisc (Daphnee)
Lynx
Master System - Game Gear - Coleco
Msx
Multi System : Atari 5200 , Atari 7800, Vectrex , Supervision
Neogeo Cd
Neogeo Pockets
NES (FAMICOM)
Nintendo 64
NEC PC ENGINE
PC GAME (youki)
PC GAME+ (angelscry)
Pinball (Future Pinball + VPinball + VPinMame)
Playstation
Saturn
SNES (Super FAMICOM)
Virtua Boy
WonderSwans
ZX Spectrum
Currently i play often with MSX game on my laptop thanks to the MSX Modules.

Even if you don't like AtomicFE , that modules are at least very usefull to discover (or re-discover) quickly some great all game and machine!. you just need 5 minutes to test a machine :
-Download Atomic
-Intall it with the default option , NO CONFIGURATION REQUIRED
-Donwload a module , install it
-Copy few roms where it is asked.
And Play! That all , less than 5 minutes of installation... no headhake... and hours of game!

Angelscry did really a fabulous work on that modules.
It would be very interresting to know that one are the most used here.