Well, eh... my question wasn't answered, so I guess I'll go for Air. I pick this one primarily due to the flight. Flying at that speed would prove quite useful for travel. You could save gas, time, and may not even need a car anyway. Also, the extra abilities, like cyclones and wind gusts, would be just plain cool if nothing else.
The space one comes in an extremely close second. Teleportation would again come in handy for travel for obvious reasons. Phasing and invisibility are very nice, but the time restraint on phasing helps put this one below air.
No problem comrade.
Ah, Storm bumps Space out of the second spot for me. Flying AND zapping stuff would be lovely. Might save on the electric bill too. The flight wouldn't be as useful as air but it would still be an immense help for shorter distances like work/school/etc.
...and you get to zap stuff.