Our local Whataburger is crap - tried it twice, horrible both times. In-and-Out is better - consistently good. Freddy’s and Steak & Shake are good also - very similar smashed burgers and shoestring fries. The best bought burger and fries is still 5 Guys, though you need a second mortgage to eat there.
Nothing beats a home grilled burger, though - ground chuck seasoned with Lipton onion soup mix, sharp cheddar, fresh tomato on a fresh bun.
Sharp cheddar. Plus 1 on that. I am not a fan of American cheese.