No, there isn't one that's "better" than the other, it's really a matter of personal taste. Crowds are about the same between the two, so you really won't notice any difference there.
Key differences...first and foremost is the wave pool. The one at BB is small, constant waves. It's like being out deep in the ocean on a moderately choppy day. The waves are non-stop but are small. TL has the biggest waves you'll ever see in a wave pool. They come about once every two minutes and are HUGE. If you aren't a strong swimmer, I wouldn't recommend going in above your waist. We all love the wave pool, because it's so much fun...but make no mistake, it is very, very powerful. It also has a sandpaper-esque floor, so don't let it drag you. TL also has water slides called Crush n Gusher. They're as close to a water slide "roller coaster" as you could get, in that jets of water push you up small hills and over the crests, it's not just all downhill. BB does not have that. BB family tube ride can hold 6, the ones at TL can only hold 4. BB has a slightly steeper/faster "big" slide than TL (not that TLs isn't fun). BB also has Slush Gusher, which is a big steep slide that has humps in it, so on the last one you actually catch a little air as you go over it. TL does not have that.
But really, they're both a blast. You won't go wrong either way.
sharonabe,
BB has lost some of it's slides because the tube slide complex in the back (forget it's name off the top of my head) is closed.