I like people that buy used games but call pirates nasty names. It's so funny. You're both refusing the publisher/developer money. Admittedly you may be giving a small amount back by purchasing DLC, though.
Buying used games gives game stores money which gives a lot of people jobs. There's a huge difference between pirating and buying used!
@ShaneDev: I honestly doubt the Imperial Guard race will be available to play as, since they are people from the Imperial City which is in Oblivion. But hey, the game isn't out yet, so as far as I'm concerned, that's an imcomplete list. You may never know.
Todd Howard has confirmed that the 10 playable races from Morrowind and Oblivion will be the playable races in Skyrim
Companies get no money off of used copies. So buying used you are not supporting shit, and could just have pirated instead, saving yourself 15 bucks. I'm not saying you can't sell used or that it's illegal, but it is a dick move.
Buying games used supports game stores which gives a lot of people jobs.