I think San Antonio is where it's at. Great atmosphere, great culture and a great school that focuses on producing strongly humanistic (and happy) doctors.
And, from what it looks like, it's much easier to be a good med student in San Antonio than in Houston. There's so many pesky little probelms with going to school in Houston that you don't have to deal with at San Antonio so that you can really focus on things you should be focusing on.