Everything would be cooler if you had a theme song for it. This could be in real life or in WoW, but nothing can make you feel more leet than a bad ass song to go with whatever you are doing. So, here is some good suggestions for the soundtrack to your World......of Warcraft.
Auctionhouse: As I have posted many times, I do a lot of auctioneering. You have to have a nice song to go along with it. I would suggest something that has to do with money.....or gold.....or something. My personal choices would be "Money" by Pink Floyd and "Mo Money Mo Problems" - Notorious BIG. There are tons of songs you could throw in here. How bout the Million Dollar Man song from back in the WWE days?
PvP: Now this really depends on what kind of mood you are in while PvPing. Are you a calculated cold blooded killer? Or a joker just having a good time? If you are the first, I recommend "If you want Blood" by AC/DC or maybe "For Whom the Bell Tolls" by Metallica. If you are the latter, then something light and funny will work. Maybe the Benny Hill theme song......or perhaps some Tenacious D.
Raiding: Raiding is supposed to feel epic and grand. You should have some music that makes it feel that way. Especially on boss fights. I like "Blood of Heroes" by Megadeth. Check it out and see why.
Miscellaneous: There are so many other times in the game where a good theme song will fit so perfectly. "The Safety Dance" by Men Without Hats goes perfectly with the Heigan fight in Naxx. "Baby got back" is a perfect song for if you see Jong running around Dalaran in his no longer Blood Elf form. "Friend in Low Places" is perfect for that failpug of the week. "The Final Countdown" by Europe is perfect for starting boss fights of any kind.
In real life it is fun to walk around with an I-Pod on and see how much you end up moving to the beat. What would your theme songs be?