If you insist that multi plat games are better on 360, then why do you have assasins creed on PS3? Anyway, that game is not that good anyway.
1. Metal gear solid 4 since this is THE must have title. A challenging game for people who are good at gaming (real gamers start this game at medium settings, not easy)
2. Gran turismo 5 proloque. It's cheap and a beauty to look at. Offers more then most full games do and you''l get a chance to get your ass kicked online by me.
3. Siren, it's cheaper then ever right now and should give you a good scare.
These choices will also give you enough budget to purchase another few good PSN titles like flower for example.
PSN name: Gazz1979 (feel free to add me, but please put your Vgchartz name in the message!)
Battlefield 2: Gazz1979
