I have one hear. It looks like it is well made and quite easy to set up. I haven't replaced my doorbell with it since I haven't had the chance to connect the wiring, but from looking at the manual and the box itself, it seems like a pretty fun item if you are looking for a big variety of sounds from your doorbell!
Just heard about this iChime digital door chime/door bell. You can set it to play Halloween sounds!
Kind of cool!http://ichime.com/builtin.html