I've been through a ton of airports in my time, and unfortunately I hardly remember any of them.
The ones I hate is Atlanta, mostly because 1) I hate the state (even though I lived there for 12 years and 2) it was in a horrible disrepair when last I went through it, as well as unclean, the bathrooms were the opposite though, it was clean and very well maintained but the rest of the airport seemed to be in shambles
I don't like the Alaska airport only because its too damn small, but they got some great cheesy fries at one of the restaurants
I liked the Denver Airport quite a bit; clean, friendly and a vibrant atmosphere
not to mention those long escalator walking things are fun to play on :P