To play Roms you require an Emulator. This site does not support those, therefore you won't find them here. However, if you follow the links below you will get to the best Emulator sites on the Web.
This french site is not so great for Roms but it has stacks of Emulators for different OS (Windows, Linux)Vimm's Lair
This site contains a lot of good emulators
Good for both Roms and Emulators