Grados are the way to go! I have a pair of SR60's with the newer earpads (more comfy) and they rock! For $100 though you could probably pick up a pair of SR80's.
CKY: Xitel headphones? LMAO! I got a pair of those with my (short-lived) Xitel soundcard, and they stunk! The cord was really flimsy, and the only way to get halfway decent bass out of them was to turn on the "force feedback" feature, and I could only stand about 5 minutes of that before it got old...
For the money the Koss PortaPro's can't be beat, if you need something around $50 they're the way to go!
Dave