MGS4 is exclusive to PS3 and can be picked up for about a tenner nowadays.
The MGS HD collection is on PS3 and Xbox360 and features MGS2,3 and Peacewalker in HD.
The other games listed, GTA etc, are all multiformat also.
I recently got a new PS3 160GB and the cheapest was HMV for €219 with FIFA street. (You can trade the game in for €20+ so really it costs <€200.)