I was born in Texas. At the age of nine, I moved with my mother and sister to Wisconsin, the land of cows and cheese. The people there were nice, and if you didn't mind shoveling snow, it was a pleasant enough place to be. Nobody understood my Aggie jokes (they don't really work outside of Texas), but that wasn't a big deal.
The only real problem I had there was with pop.
Or should I say, with "pop": the soda there was as good as anywhere else, but they insisted on calling it "pop". To my ear, this was a travesty of the highest order; it set my teeth on edge. They also called water fountains "bubblers", but I would have forgiven that. I'm a forgiving person.
Naturally, I tried to explain my concern to my friends. In Texas, I told them, we call everything "Coke", and that doesn't refer specifically to Coca-Cola: it refers to anything that's bubbly and has a lot of sugar. I'm sure this naming is the source of great consternation to the Coca-Cola's trademark lawyers, but that's just how it goes when you've dominated the market for that long. The Kleenex people have the same problem, but I'm not too worried about them either.
Needless to say, the "Coke" thing made no sense to them, and they kept right on with "pop". I finally had to settle on "soda" as a substitute, since I didn't actually like Coca-Cola and didn't want to be misunderstood. But it always bugged me, and to this day "pop" makes my ears jangle.
That's why I was thrilled to hit upon www.popvssoda.com, where some enterprising individuals have created a county-by-county breakdown of generic soft drink name usage for the entire United States. I wish this had existed back then, so I could have proven my point indisputably and with charts. They even used red as the color for the "Coke" counties - nice touch.
Nevertheless, I say better late than never. Their research is probably completely unscientific, but it confirms what I already knew to be the case: Texans drink Coke, even when it's Pepsi.
Disclaimer: I don't actually drink Coke or Pepsi, but the regional differences in names for water and tea aren't nearly as interesting.