Long-term, I don't think. I'd want to live anywhere in TX but Austin. Dallas and Houston are basically just big cities, not too different from places like Atlanta, where I live now. They're ok, but nothing special.
On the other hand, there is a lot of great medicine in those cities. The Texas Medical Center in Houston is as impressive as you'll find anywhere in the world.
San Antonio is another huge city, but more laid back. Pretty diverse place, culturally. It has some fun stuff, and also not bad for medicine, but it isn't really my kind of place for long-term.
Realistically, I'm sure I could make a happy life for myself anywhere, but I still haven't been anywhere as cool as Austin. The thing about Austin is that there's something for everyone. It is culturally and politically diverse, and it still retains some of its small-town feel, despite the fact that it has exploded into a huge, fast-paced city.