Back in August 2006, development studio Volition released a game called Saints Row. Now, this was a very good Xbox 360 game. Getting mostly positive reviews, it managed to shift 1 million copies two months after release.
The trouble with Saints Row was that its core gameplay borrowed a lot from Rockstar's Grand Theft Auto series. But unlike plenty of other GTA clones, this one kind of had style and soon became a critical and commercial success.
Development studio Volition is now working on a full-fledged sequel, which is heading to both Sony's PS3 console and Microsoft's X360; the original was announced for the PlayStation 3, but the project got dumped to make way for Saints Row 2.