In-N-Out is without argument one of the best large fast food corporations around. A number one will run you just over $6, which is about what a Big Mac costs, but the burger and fries are infinitely superior to McDonald's. However, with that being said, if you're in California or Arizona, go to Habit Burger. It's no more than a dollar more than a number one at In-N-Out but the burger is noticeably better.
Sparknotes: Habit Burger>In-N-Out>Five Guys