I like airsoft and paintball. Currently, I'm into paintball, and in my opinion, its more enjoyable. I guess a big turnoff to me is people cheating. Don't get me wrong, cheating happens alot in paintball, but its easier to catch them cause they have to wipe the paint off. Hey if your starting out, go airsoft, thats what I did. Its wayyy cheaper, more realistic (if you like realism), doesn't hurt as bad (usually), and can be played almost anywhere. Downsides are that you have to play with players who have sportsmanship since its easy to cheat, paranoid neighbors might call the cops on you, and some parents think its too realistic/dont like the idea of kids shooting each other with lifelike firearms. Thats my $0.02
Also, paintball is alot more common where I live (heck, smart parts headquarters is only an hour away from me), and I dont think there are any commercial fields strictly for airsoft around here.