Fast food isn't about tasting good, it's got a certain comfort to it. I enjoy a McD's double hamburger until I'm done with it, then I feel like garbage for the following 3-4 hours. I have to imagine it's akin to addiction (I seem to recall reading an article that they are tailoring the stuff to be addictive).
I've been avoiding fast food with a 97%* success rate. OK, that number is made up, but I'm batting 1,000 for impulse buys at fast food, and only a few times for actual meals. The meals have been as good a choice you can get (grilled chicken sammich or salad, no fries; or the "healthiest" breakfast sandwich at DD).