I've also seen some nice fences by these guys -
http://www.blackwellfencing.com/I like Sunnyvale I posted above because it looks like an actual company; not some guy working out of the back of his truck (see below).
As for companies to stay away from, I used one called Reliable Fence that was recommended on here about 2 years ago, and the fence has not held up well at all. I had to call them out about 3 months after install because the stain looked terrible, and they said they only warrantied install, not materials, and they considered the stain a material. It looks like they may have changed their name to Texas Fence Masters.
[This message has been edited by slschultz02 (edited 3/21/2011 8:38p).]