McDonalds. I know its terrible for me, but i love it and i don't know why. Its like Harley-Davidsons, i know their just over-sized American pieces of crap, but for some reason i love them.
However the best Burgerking meal i ever had would probably be better then the best McDonalds meal, but Burgerking around here is extremely inconsistent, as is White Castle, which would probably be the best food ever (forget fastfood.) If White Castle could figure out how to actually make burgers consistently good i'd probably spend 1/2 my time their. I probably only get a proper White Castle burger 1/10 times though, but its worth the gamble.
I'm gonna have to go with Wendy's as well. I used to work for them, and unlike most people's experiences with working Fast Food, I came out with a more positive impression of them as a chain. Burgers are never frozen, Salads and Chili and baked Potatoes are all made fresh daily, Fries have a mandatory 20minute rotation before they're supposed to be tossed, etc.
I went to Mc Donalds and pizza hut once, and hated both. Unfriendly, silly clothed staff. Unclean bathrooms with greasy signs telling the staff to wash their hands. Dirty tables and uncomfortable chairs. Twice as much garbage as food. Watery cola in paper mugs. Food looks much better on picture too and makes you want to vomit once you start realising what you are eating.
I'm very glad here in Belgium we (still? :/) have lots of private owned locations for cheap food, like the "frietkoten" where you can get real fries.