If your looking forlegal public domain roms theres the massive PD Rom Pack Archive full of Public Domain Rom Zipfiles containg roms for Atari Lynx, Atari 2600, Colecovision, Commodore 64, Gameboy, Gameboy Advance, Genesis, Intellivision, NeoGeo Pocket, Nes, Nintendo 64,PC Engine, Snes, Vectrex and finally Wonderswan Roms.

The zip files contain thousands of free and legal roms.

So head on over Here to download away.