Korg KDM2 Digital Metronome - (New)
I have the older model of this metronome and I like this one better.  It has a digital dial, so you can get any speed.  It has a volume control and it gets really loud so you can hear it even during forte passages. It has a button that you can tap out the tempo you want and it converts it to a number, so you don't have to guess. Overall a great metronome and Amazon had it at a good price.