Xbox Live Jump In Night

[Bube]

Ok, I may buy a new 360 game, and even though it hasn't happened yet, I want to at least have a chance to play with you people. Which would be the best - CoD4, GTAIV or Orange Box? I really want CoD4, and even though TOB is great value, I can't play Half-Life games as they make me dizzy.

The purchase isn't definite, I might not buy it at all. But there's a chance that I might, so I'm asking for opinions. And which game is played more often?