Texas: Burger Street
There's really no comparison between In-N-Out (privately owned by the Snyder family) and Burger Street (privately owned by William R. Waugh), other than the fact that you can (optionally) order from the passenger window at both. In-N-Out is busy ALL the time, partly because of their attitude (and well, okay, the burgers and fries ain't bad either). Their restaurants have a much larger staff, and the greeting at the drive-thru microphone is "How ya doin?" rather than "What can I getcha?". I remember their bumper stickers, where hormonally-challenged mutants would change (with the help of scissors):
In-N-Out to In-N-Out
Kansas (and points east): White Castle
Whataburger is also a joke; sadly, there's little intent to do anything other than deliver SoggySaltyBurgers as fast as possible, although they are open 24 hours, like White Castle (which does have an entertaining culture). Go to a White Castle at 3:30am, order 20 White Castles (about 3 bites each) and play your harmonica. Here in Dallas, the only White Castles are available in the frozen food section of Kroger, and it just ain't the same. Not sure what Kroger would do if you showed up with your harmonica in the frozen food aisle, middle of the night. I suspect the word is "jail".
There is one area where Whataburger has it all over White Castle: their fine breakfast cuisine (it's enough to make your cholesterol pop right out of your veins). The pinnacle of breakfastdom still rests with Dairy Queen, though (where the bulk of civic business is conducted, outside the major Texas cities). Some would argue that the only real Tex-Mex fast breakfast can be had at Taco Cabana (try getting huevos rancheros at McDonald's!).
Unrelated spot: Texas Twisted - How the West Was Weird