I haven’t hung out with him, but once in the bathroom of Trees while he was transmogrifying from Jack Heath to Horton Heat, he used the door of the stall I was in as a hanger for his clothes. That was a bit awkward, but not too much since I was fairly well toasted. 
I’m also a native Texan and (really bad) guitarist, and I’m not 100% sure I can attest to our 100% originality. Just sayin’. 
Likewise. Opened poll just to vote for Rhett and his cohorts and had to click Other.
The Reverend’s shows are some of the most fun concerts that I’ve ever attended.
Oh, while Joe Walsh isn’t a Texan, his bandmate Don Henley is.
This Will Destroy You
Not on the list Understandable given their niche style and relative anonymity.
Those are some difficult choices there. Much talent in that (abbreviated) list. I don’t know that i’d put all these guys in the same catagory (Texas Rock), but I agree w/ you that a lot of talented musicians have been Texans.
Well, i jumped right out and said, “Toadies” ! Then I read a little farther and remembered shakin’ my booty to Bob Wills a few times. I can’t say that I remember dancing to the Toadies (smoking to the Toadies maybe, but no dancing). And then I thought of the occasional tear or two that appeared while listening to ol’ Willie share his feelings though his songs. This is a tough call for sure.
Though i’ve always enjoyed the Toadies, I can’t say they were as talented as some folks on that list. They did a great job w/ what they had and they were great songwriters (did Todd write it all?)… *Tyler *and Possum Kingdom tell quite the story. That, combined with their “no bullshit” approach, made their music stand out to me (“We’re coming home on a plane crash”!).
But you did ask for favorite, and not “the best” so I’ll stick w/ the Toadies for now. Of course, sitting on the deck w/ a cold beverage later today, I might be more partial to brother Wills. And after a couple more beers, I’ll be looking to hear some Willie. And then i’ll want to hear Willie sing (Townes’) Poncho and Lefty, ha!
(p.s. King’s X… one of the best things to come out of Katy, IMHO. And I am a Fool for Those Stockings that ZZ sings about)
Polyphonic Spree
Stevie Ray’s musicianship, energy and emotion wins for me. ZZ is is great and a fun package, so that would be number two.
You’re going to make me choose between Willie Nelson and the Butthole Surfers? What kind of monster are you?
I always play ZZT if I end up in Texas. Willie works anywhere.
While tempted to choose Stevie Ray Vaughn, it’s a safe pick… I’m gonna go off the board and give a shout out to Los Lonely Boys.
Also love the Rev’rend!
But I think leaving Lyle Lovett of this list makes me wonder if you’re not from Texas. 
Also gotta give a tip of the hat to James McMurtry and Robert Earl Keen.
I voted “You clod!”
RIP Dimebag Darrell, a truly prolific guitar player who brought actual emotion and style to the sometimes mechanical and robotic world of heavy metal guitar shredding.
I don’t know if it’s still in use, but I recall that Pantera had composed a song for the Dallas Stars of which a portion was played at some point during each of their home games, due to one of the band members’ friendship with one of the Stars’ players at that time.
Lyle Lovett and his Large Band. I don’t know why it was left out . . . oh, that’s right. You’re not from Texas.
As several others have already said, the answer is The Rev. Horton Heat.
You and the OP both misspelled this. Carpetbaggers!
I went to college there, and back then I certainly would’ve picked David Garza. These days I’d have to say the Reverend.
It’sa fair cop. I’m from the Northeast.
Commander Cody brought Asleep At The Wheel to Texas! Ray Benson heard Western Swing records at home in West Virginia & started a band. Then they moved to California–because that was where the hip kids went. Commander Cody hired The Wheel to open for them on a tour. I remember the Houston gig–some “older” folks came to see the Wheel. They needed no explanation about Western Swing–they just danced. Bob Wills was still alive in those days–hospitalized & past playing; but lots of ex-Playboys were still around. Willie Nelson told Ray he ought to move to Texas–Asleep At The Wheel continues.
Since we’re talking about Texas bands still recording & touring–let’s not forget Brave Combo!