I was talking to a friend who just went back to California after visiting Texas. She said that the first thing she did after landing in Texas was to find a Sonic. She said that more than anything, Sonic is Texas fast food. I find it hard to deny, since there are 4 within two miles of my house. Then, I remembered Sishir Chang's post about going to Whataburger as soon as he got to Houston. It might be considered the Texas fast food, especially since it is headquartered in Corpus Christi. Last, the center of every Texas small town, Dairy Queen. Dairy Queen is all over the country, so it's hard to find someone who must go to Dairy Queen in Texas. But it's hard to leave it out, too. Any that I forgot?
Sorry, Sonic is Oklahoma fast food. It was founded there and their corporate HQ are there. The fact that there are so many so close to your house isn't really unique to Texas. It's the same way across Oklahoma and Arkansas, the two other states where I spend the most time. Additionally, my vote is for DQ for a fairly unique reason. While there are DQs in many states -- the ones in Texas have the best/most unique menu. Most of the best items on DQs menu you can't get in other states. For example, in many of the northern states, I've found that the DQs have very limited menus. Additionally, in Arkansas, I haven't seen any of the DQs with Steakfingers, which are my favorite non-desert item from DQ.
I don't think Taco Cabana has a widespread enough presence across the state to really qualify. I'm not aware of a Taco Cabana within 2.5+ hours of my hometown.
According to Wikipedia, the Texas State Legislature has named Whataburger a 'Texas State Treasure'. This is not true, as far as I know of the other two. The first Dairy Queen was in Illinois. The first Sonic was in Oklahoma City. and The first Whataburger was in Corpus Christi, Texas.
maybe it's because i was just in centerville and ate at a dairy queen for the first time in forever, or b/c i never eat at whataburger, but i ended up picking DQ for the "Texas stop sign" aspect of being in every small town. maybe if whataburger's burgers were ever hot, or even warm, i would've picked them.
There's DQs and Sonics in California, but no Whut-aburgers. Whataburgers are definitely on the checklist when I visit. Also on the list: ribs, Blue Bell, and all you can eat buffets ($5 pizza).
Sonic is definitely more Oklahoma than Teaxs. There's almost literally one on every street corner up here (in fact, I can think of a few Sonics that are directly across the street from each other). Plus, the company is headquatered in Oklahoma City (there a bigass, eat-in Sonic next to their complex). Edit: i see others have mentioned this. If anything is Texas it's Whataburger. I don't really eat there (too pricey), but I hear it's good. I'm more of a JitB guy myself (btw, is that a Texas fast food restaurant? I haven't really seen them that much anywhere else).
I went to junior college in a small town in east Texas. They had one Whataburger and TWO Dairy Queens.
Personally, I loved going to Cancun and seeing "Muchoburger." All they did was take the Whataburger's "W" and flip it. I thought it was pretty funny.