It was so easy to find them thats why I ask.
So really theres nothing legal about MAME game wise.
Mame in and of itself is perfectly legal and breaches no copyright. However the vast majority of game roms and bios roms (bios roms are the underlying operating code for different types of arcade hardware) are still subject to copyright so are technically illegal to download without the explicit consent of the copyright owners, although in many cases its not financially viable for the copyright owners to pursue legal action against people who are doing so, so mostly they simply turn a blind eye, especially where the roms are for older games that no longer make anyone any money.
Copyright holders will generally try to dissuade romsites and almost certainly threaten legal action against anyone making money from the enterprise though.
Its perfectly ok to discuss games and game roms here, but it breaches the forum rules to discuss how or where to obtain them.