Which should I join? Army or Air Force?

I'm looking into college ROTC and I can't figure out whether to be an Army ROTC, or Air Force ROTC. I guess what I'm looking for is the more rewarding job. Is being an officer in the Army, or the Air Force more rewarding? Which do you rank up faster in? Which one has more action involved? Which one would look better on a job resume after I get out? ECT. Any help would be much appreciated.