Now untill June 12th you can play 500+ games for free at Gametap.com
These games are legit and are licensed by thier respective owners. There are over 500+ game to choose from and many of them are fantastic. Games like Street Fighter III, Gunstar Heros, the Fatal Fury series, Contra: Hard Corps, Strider, Darkstalkers, Beyond Oasis, Castlevania, Vectorman and many more. Check it out and let me know what games you are most interested in.