We've been gone from Houston for almost 11 years. When we lived there, however, we were very pleased with Norman Frede Chevrolet on Bay Area Blvd. in Clear Lake.
The automotive board can also help. When you find a vehicle you like, post VIN and other details and there are guys that can tell you invoice price to help you in negotiations.
We just bought from Munday Chevy and had a very good experience with thier internet sales team. We picked out the vehicle we wanted, told them what we wanted to pay, and they made it happen. Very nice with follow up customer service also.
This was after walking from a deal with Munday b/c their finance guy was trying to dick me and my dad around when we started looking at numbers on the contract, etc.