For whatever reason, I've had more flying dreams than any other specific dream I can remember. It probably helps (or affects the statistics, at least) that there are apparently fairly specific rules that govern how I fly, and in fact it's often more ground-skimming levitation than flying.

I'm almost always really surprised (and disappointed) when I wake up to find that it wasn't real (again). It seems that I find that sort of locomotion fundamentally plausible (for appropriate values of 'plausible').