I would go with fallout 3, I had left 4 dead 2 for the 360 and couldn't really get into it, I ended up selling it a week later after I beat it.
Hmm Well, if you want a lengthy game Fallout 3 would b best you can probably DL mods for it nowadays. i have it for Xbox 360 and it's a great game but if ur looking for multiplayer obviously Left 4 Dead is the one for you. or.... Multiplayer wise you could go for - Counter Strike, WoW (Of course...), Aion, Warcraft III still rocks (to me at least), wait for Starcraft II? there's a plethora of online games that are stunning but I dont know what u prefer lol. as far as Fallout 3... Oblivion is good for comp. you can mod it and add crazy cool stuff. idk much of the RPG-ish computer games so good uck on that!
