I've heard some of the Radio Schack ones and they are pretty good. I'm not sure if they come with their own power supply or if they have to be wired at all though.
I purchased my Icecap variable speed fans and could not be happier. I have yet to have seen a fan that matches it for quality...By the same token, I never went out and looked
!
For me, having the tank in the living room, the spousal unit was not going to stand for more noise than we already have, and I have a laziness factor to contend with as well. All these added up to plug and play fans from Icecap!
FWIW,
Rob