If you are looking for a low cost reverb, you won't find better then Valhalla...
If you are looking for a really good reverb in the middle price range there are a lot of choices..
These are in my order of preference
112db - Redline Reverb - $150 - sits in a mix really really nicely and sounds very close to hardware.
Lexicon LXP - It's the sound...lush, warm, and inviting - can be had for about $130 or
you can get Lexicon MPX for about $65
2C Audio - Aether, Breeze, B2 - very nice reverbs
PSP Easyverb is a nice verb for about $60
I've heard great things about Phoenix, but haven't demo'd it yet..it's about $200
There are a lot of really decent FREEVERBS out there also...
It's all a matter of preference....and the sound YOU are looking for...
And I agree completely about Breverb...I don't use it at all...if you want to do a whole lot of adjustments you can get an ok sound out of it...but, to me, it's too "metalic" and cheap sounding.
Bang for buck...you won't do better then Valhalla IMHO...but that's just my opinion...