For me it pretty much depends on the type of game it is. If it's something I've been looking forward to and I have to plunk down $60, then you can bet I'll be squeezing every inch of that game in the first play through. If it's something I got on the super cheap, I'll usually just play the game to beat it and be done with it so I can move on to something else. I do find that games that have a very rich and detailed world, i.e. Deus Ex, Skyrim, etc, are the easiest to get lost in and really spend time with.
