I'm feeling like this question has been asked quite a few times lately. I'm 22 now and just getting back into the sport after a 5 year leave.
Houston has, as far as I know, deteriorated slowly in the way of good fields, people are staying loyal to the places they have always played at.
Having said that,
Airball: 5J, Twisted, Zone South, TxR, Galveston Island, and Xplosive (wouldn't try this one, haven't heard good things)
I play at tanks pretty often, but there's no airball and spools is starting to get old so I think this weekend I'm going to try out one of the above.
Realistically, it depends on where you live and how far you are willing to drive. Pbnation has a pretty good way to find them >>> Paintball Fields & Stores <<< type in your zip and it will give you detailed info.