Kongregate - Free games!
Kongregate is an online games hosting website owned by Gamestop Corporation, which allows users to upload user-created Adobe Flash, Java or Unity3D games. It features an API that Flash and Unity developers can integrate into their games which allows users to submit high scores and in some games, earn achievement badges. Badges and local score submissions are only available on games whose developers choose to use the Kongregate API
www.kongregate.com/