+1 on Southern Star in Conroe, with caveats.
The brewery is a glorified shed, and they will point and say, "Well, those are the fermentation tanks, that's where we boil the wort, and this is Sam. Sam puts the beer into cans. Would you like some samples?"
BUT, if you go on one of their anniversary days, it is a real party. When I went in March a few years back, they had a bug boil, a live band, and no end to the samples if you had one of their glasses. It was a wonderland of jollity.
Last time I was there, and I think it's the same today, they were filling the cans by hand, two at a time. Also, if you still haven't tried Southern Star's PA or Stout, you are wrong. So very, very wrong.