I've tried the Verrbzilla and thought it was pretty good. If I need a reverb pedal though, I go to my old Peavey Reverb, I think it is the SDR-16. Sixteen modes of digital reverb. Needs it's own power supply, but that about the only semi-bad thing I can say about it.
The Ducking Reverb on the Line6 Verbzilla is the bee's knees! I originally got the pedal thinking I'd use it every and then, but it's just one of those things that sounds so GREAT I want to leave it on all the time!
I have a TC Electronics Nova Reverb and I like it alot. I don't like reverb all the time, but every now and then, I really go for atmospheric tones and the Nova provides a lot of options for tweaking what kind and how much reverb you want.
As Moose points out, the Boss FRV-1 is really sweet.
The old Hardwire Rev is also a very nice unit.
If you do not mind using a real 19" unit, and a blend box that is also a cool combination.