Well, I dont like fast food at all, but if I had to choose one, I would have hit Checkers/Rally's(which isnt up there). But still, I would have picked none....i love ramen and cereal too much to go outside to spend lots of money on grease bag food
Other: Chick-fil-a, they always have a nice clean, fun play area for my kids, generally indoors and behind glass, so it's not hard to keep an eye on the rugrats while I eat (in peace.)
But there's a Krispy Kreme near my house, and nothing beats the fresh hot donuts, I mean damn!
In no particular order What-A-Burger, Sonic, In-n-Out, and White Castle (only when I'm back east). What-A-Burger may be the winner since all of their stuff is quite fresh and they have the best onion rings by far!
A lot of those aren't available in the town I live but I love Burger King (holy crap, the burgers actually taste good that I'd go to the other side of town for it) or KFC.