Sabine Zipbeat
http://sabine.com/zipBeat_index.htm
- I used one of these for a long time. I would still be if I didn't lose them constantly. Very reliable, have an ear phone jack, adjustable syncopation, etc. Very good, nice and loud, and not to annoying to listen too (which is key)
Wittner MT-50
http://www.theguitarfiles.com/product_id-769.html
- Bought this as it was the only one available when I needed one a few months back. Very reliable, not as many crazy options as the Sabine; but works great. Again, the key with any of these is that the "click" of the metronome is not to annoying to listen too.
Good luck! :o
Douglas Showalter