Electronic Drum Sets

I have the Roland vDrums Pro set. I really love the Rolands because of the natural feel of the mesh heads. Also their sounds and COSM technology (allows you to change the shell, heads, muffler, room size) is really cool. Also you can use your hi-hat pedal to adjust the pitch in some sets (kind of like Timpani). There is a new model out and I'm considering upgrading mine. I've had them now for about 4 years and love them.
On the other end of the spectrum as far as price (because electronic drum heads can be very expensive), you can build your own cheap drum pads out of practice pads and piezo buzzers - it's pretty easy because I did one myself. I can't really comment on how nice the feel is, because I'm a guitar player; not a drummer, but a drummer that I used to know used some of these and claimed he liked them as much as the Rolands. http://www.cse.ogi.edu/Drum/FAQ/triggers.html