Ok, this is a great one! :-)
I'm a bit in dubio regarding this... But I picked one!
I was first thinking about invisibility, but only as long as you can hold your breath... Would be nice, but not long enough. I would be able to improve it a bit, but quite sure I wouldn't be able to extend it to 10 minutes ;-)
Time travel seems nice too, but being able to visit each timeperiod only once, I might get problems with that... :-)
So I chose Flight! I often dream that I can fly, and I like the idea. And only being able to eat bird food might just help me losing weight too!!!! ;-)