That Re-Play factor

I make this thread in pretty much every console forum I go in. :3

What games do you think have the "Re-Play" factor? You know; the games which you can complete and then just pick up the controller and keep playing them over and over again.

For me, Gears of War 2 has excellent Re-Play factor. I've completed the storyline twice now, and I often can be found playing on Multiplayer against the AI. It is still fun to play, and the game itself just makes me think: "Wow, awesome D:" (yes, I think in smilies).

Another game which has the "Re-Play" factor for me is GTAIV. Although many people strongly dislike the game, I do not believe you can go wrong with a GTA game when it comes to the possibilities of playing over and over again.

So, what games do you think fit into this category?

too human, the story is very short and not so well put together because it is the first of 3, but the whole game is just a giant horde mode so it really makes no difference when replaying, it's a great game to play with a friend too. in multiplayer there are more and harder enemies.

The Lego series by Traveller's Tales. You get to a place which none of your characters can access to, play the mission again in 'free play' and one of the several characters should be able to get in. Plus collecting.

Fallout3
Halo3
GoW2
GoW
Halo Wars

and....

Mass Effect.

Campaign wise: Gow2, Battlefield: Bad Company, Fallout 3, any of the Lego games, Left 4 Dead etc.

For multiplayer: Pure, Gow2, BFBC, Rainbow Six Vegas 2 etc.

Defo Left 4 Dead though, although it only currently has the 4 campaigns and versus its still highly replayable I reackon. Just really want a couple of more campaigns for it!

Gears of War (Online)
Left 4 Dead
Rock Band 2

Thats all I can remember right about now.

For me it would be....
Left 4 Dead
Dead Space
Fallout 3 (clocked 92hours in first playthrough and doin it again as we speak)
Gears Of War 2
Call of Duty WAW
And everyone says mass effect, I own the game but never got into it, ill have to give it another shot, I don't think I ever left the citadel place