Which of these games should I get for the xbox 360?

Well if you just want to have fun and play online games for fun, you shud get Left 4 Dead because it's extra fun killing zombies. If you prefer single player games (RPG)'s then its a big choice between Fable 2 and Fallout 3. Call of Duty: WAW is alrite but if u have COD 4, i prefer you stay with it. and mercinaries is