[In the Drunk Tank]

Got the idea of this from the "Movies you can watch over and over" thread, what games do you consider to have the most replay value?

For me it's usually the games that offer the most choice throughout the story, or the ones that can offer different endings and different paths, so games like Knights of the Old Republic I & 2, Mass Effect, Dragon Age: Origins and to a lesser extent the Fable games

There's also games that I can play after completing but not really doing anything, Saints Row being the main one, I've played that for ages even after doing all the missions.