Real Ale is a great brewery, if they can find Sisyphus, I highly recommend it, but it's pretty rare.
St. Arnold has some alright stuff, nothing too amazing though, but they do make a nice Texas Brown.
Rahr is my local favorite, but not sure if it gets to Houston, if so, Ugly Pug is great.
Souther Star Pine Belt Pale is good (reminds me of Oskar Blues Gordon), but another hard one to find, as it's the only beer they even package.
And I know a lot of people don't like Shiner, but their Black Lager is awesome.
There's a few others, but Texas isn't really known for it's great beers, and our alcohol laws suck, it's a lot of BMC around here.