Gimme some fin, Clista! This question totally rocks!
I've visited both
Disney's Blizzard Beach Water Park and
Disney's Typhoon Lagoon Water Park with my own family (which now includes 2 teenagers) and we really have loved them both. There are lots of similarities between the two, like the hours, availability of
PhotoPass photographers during the summer months, good Quick-Service dining options and great theming, and I think you'd be happy with either one.
That being said,
in general, I think Typhoon Lagoon tends to be more appealing to adults and teens. One of the main reasons is the massive 2.5 acre Surf Pool, which sends out waves as high as 6 feet, and is surrounded by a sandy beach. If you can manage to convince your kids to wake up extra early, you can even arrange for surfing lessons before the water park opens. There's also Shark Reef, where you can get up close and personal with the sharks, stingrays and other tropical fish as you snorkel, and the Castaway Creek lazy river that snakes around the whole water park. Not to mention the usual water slides and tube rides.
Blizzard Beach's main pool is much more quiet and calm, which makes it especially great for younger ones. There are 2 separate play areas designed for different ages of kids, Tike's Peak and Ski Patrol Training Camp, plus rides that are designed more with families in mind...except for the ultimate water thrill ride, Summit Plummet, which is basically a 360-foot long free-fall from the top of 12-story Mount Gushmore. Yikes!
I hope that helps, Clista. Just keep swimming!
Beth