I personally have never downloaded any DLC (with the exception of MM9&10), but my reasoning is simple: you can demo most of the games, now, before you buy them, but you cannot demo any DLC. Or at least, not as far as I'm aware (I haven't looked that hard). And I don't feel like wasting my money on getting "ZOMG A NEW GUN" or "ZOMG A NEW CHARACTER" or "ZOMG A NEW HAT!"

Yes, some of the additional maps and campaigns and whatnot sure sound pretty nifty, but from what I remember when people were talking about the different DLC for Fallout 3: "This one is crap, this one is crap, this one is crap, this one is good." Well, thanks in advance, guys, but I'd rather just save my money and buy a completely new game. Maybe when I'm piss broke down the line and all I have to spend on a new game is $10, I'll download some additional maps and campaigns for a game I already have.

Also, to whomever said that they miss Doom: I you. I you hard.