Christina Uticone tried Whataburger's chicken club and pineapple shake, sending commenter Rgwalt into a kind of dream state:

The grilled chicken sandwich topped with grilled peppers and onions is another limited time option, and it is fantastic.  I recommend getting it with jalapenos, also grilled...

As far as the regular burger, I also recommend eating in, or taking it "to-go" as I did in one of the most satisfying food experiences of my life (and overall memorable moments):  I had just closed on my new house, and had spent the weekend cleaning, installing, adjusting, moving, and generally busting my ass at the new place.  Sunday evening rolls around, and I realize that 1) I need to get my car inspected and 2) I am starving after not eating all day.  The solution? A trip up to the Shell station at North Shepard and 610, and the adjacent What-A-Burger.  After dropping off my car for the inspection, I walked over to the What-A-Burger and got a single with cheese, all the way (lettuce, tomato, fresh onion, pickles and mustard) to go.  I DEVOURED that burger with reckless abandon on the short walk back to the shell station.  That experience was surreal for me... The burger was absolutely perfect.  The veggies were still cool and crisp, while the meat and cheese were still piping hot, oozy, and juicy.  The flavors were all still distinct, but played together in perfect harmony!  Combined with the hunger, beautiful early evening weather, the unexpected spontenaity of the moment, and the sense that I was truly "walking the earth", the experience of eating this burger will never be forgotten.

Well, Rgwalt, since this was one of the best moments of your life, we are going to assume that your car also passed inspection.