Champions Energy is supposedly really good and they are doing everything they can to be a great community sponsor. I know they gave a lot of free electricity to the our little league this year and the CEO came out for opening day.
Personally I still have Reliant and the only issue I have is when there is an issue they still have to call Centerpoint to fix it (as do all of the companies in Houston).
I've used Star Tex for 2+ years, and the last time I checked their lowest month-to-month rate under $0.09/kwh. As mentioned, Champion Energy has really been pushing lower rates and local service lately. If you go to their site atThe Link and use the discount code "1560" it gives you their lowest current rate (I think).
In general, all electricity providers in Houston are serviced by the same companies if you have an outage (mostly Centerpoint, I think). You are just choosing the lowest middle man for your rate. You just want to choose one that won't be going out of business anytime soon.