Wendy's until they decided to use potatoes which were not peeled for the fries and called them "Natural Fries? BS. just cheaper to buy that's all. Now we stop at Mickey Ds but I usually have the Southern Fried Chicken sandwich and not a burger. The burger meat is too nondescript.
Generally speaking, independent locally owned places are best. There's a local place where I live which has real milkshakes and burgers, but the best place is a place called Cruisers in Portland, Oregon. Yummy burgers, freshly made from real meat and fresh fries, onion rings, and shakes.
If you ever hear about "5 Guys", don't go. It really REALLY sucks.
And how many other burger places get a movie made based on an epic journey to get there to eat?