Usually Fly/Transport are one of the first ones mentioned in these kind of threads, so I'm a bit surprised no one's said them yet.
As for myself, I think that Recover would be my boring, yet effective choice. Any time I'm sick, hurt, or tired? Boom. Recover. I could see it coming in handy all the time, to the point where I wouldn't be quite sure how I lived without it.
If I had to go for any other move though, then Metronome might be fun. Sure, I'd have no idea what I was using it for, but it'd be neat to be able to randomly breathe fire, fly around, shoot ice beams, etc., without regularly knowing how.