Replaying Games?

Are you a game replayer?  Do you find yourself going through a game more than once, whether it's because the game was so fun or because you want to get an achievement?

I have to admit that I'm not really into replaying a game that much.  I heard people talking about two or sometimes even three playthroughs of super-long games like Oblivion or Fallout 3 and it just boggles my mind.  What's the point?

I realize that some games offer you the option of being light or dark, hero or asshole, and that's ostensibly for the purpose of replayability, but I find that's not enough for me.

I know there are achievements for the different types in some games (like Fallout 3) that might make you want to do it, but I just can't muster up the energy.  There are too many great games out there waiting to be played!  I started a second character in the original Mass Effect so that I could be a dick, but I didn't make it too long before I got bored.

I am an achievement whore enough that I did create characters to do all of the various beginnings in Dragon Age: Origins and get those achievements.  And the same for Borderlands and getting the achievement for getting kills using your action skill.  I replayed the game with each character type just long enough to get those achievements.

I've played through Borderlands once and reached Level 36.  I know the game gives you the chance to do multiple playthroughs so you can continue to level your character up, and I have done that to some extent, but the interest isn't totally there (could it be because the game's kind of tedious?)

Do you replay games like this?