Right now I'm using an older m-audio uc-33. It's ok for faders and knobs, but lacks in the buttons (kills, cue, load, etc) and speed (jog, nudge) department.
What is your favorite or preferred controller, keeping cost in mind? A quick look around the web makes me think the Numark Stealth Control and Behringer BCD3000 might be good contenders. How do the Hercules products compare, and are there others worth checking out?