Both water parks are great. If you want more water slides and action, pick Blizzard Beach (BB). If you want more relaxing, pick Typhoon Lagoon (TL). Either way, you won't regret it.
We absolutely love both Disney water parks. They are the best in the world and just as enjoyable as the 4 major theme parks. What distinguishes them is theming. Most water parks feel like cement with a bunch of water rides stuck in the middle. WDW avoids this with extensive theming, lots of greenery plus sand, careful maintenance, and incredible attention to detail. If you enjoy the "little" things Disney gets right at the major theme parks, you'll enjoy the water parks.
Our favorite water park has evolved as our children have matured. When they were very young (under age 6), Tikes Peak (TP) in BB was the way to go. Lots of water rides targeted for the very young. TL has a little kid's area, Ketchakiddee Creek (KC), but our children did not enjoy this as much. First, there were fewer water attractions so there was not as much for them to do. Second, the water cannons in the center of KC were used by groups of 8 year-olds and their parents, even though KC was supposed to be for the under 6 crowd. (Our 3-to-5 year olds could not even reach some of the water cannons so I understand why the 8-year-olds used them.) Disney clearly learned a lesson from TL when they built TP, increasing the number of water attractions and gearing the entire area for the very young.
As our children outgrew TP, our focus shifted to TL. They enjoyed the main wave pool and the lazy river ride (Castaway Creek). BB has a similar lazy river ride but their wave pool is not as much fun. The main pool at TL produces one large wave every couple of minutes while the pool at BB produces continuous swells that can make you sea-sick.
As our children grew more (think pre teen), our attention shifted back to BB, this time to the Ski Patrol Training area. As they reached the magical height of 48", our attention remained focused on BB, but this time on BB's big thrill rides such as Summit Plummet.
It's hard to decide which water park is our current favorite. In general, TL feels more relaxing (our teenagers like to sunbath as much as anything else) but we enjoy the big thrill rides of BB as well. If the weather is warm, we plan one entire day at each water park during longer trips. They serve as nice mid-week breaks from the constant "go" of the 4 major theme parks. You don't have to get up as early, stay out as late, or walk as much. The water parks offer more entertainment than the resort pools and the water is a great way to beat the Florida heat!
The water parks are tougher to enjoy during shorter vacations; they need an entire day to be really appreciated. Many people squeeze them in during the afternoon, sandwiched between morning and evening trips to the major theme parks, and don't get to enjoy the water parks to their fullest. Also, this makes the water parks the most crowded in the mid afternoon and so a lot of people see them only when they are packed. Morning crowds usually aren't too bad and the water parks tend to empty out for their last hour or two. We have photos of us being the only ones in the lazy rivers; these were taken during the park's last hour.
My favorite WDW ride (including the 4 major theme parks) is Teamboat Springs at BB. Your sit with your family in a large circular rubber raft as you descend down a long, twisting slide. My absolute fondest WDW memory is seeing the faces of our young children the first few times we road Teamboat Springs together. Pure joy!
If you have to choose between the two water parks, Shark's Reef at TL should be mentioned. You get to swim with sharks and other sea creatures! BB has nothing like it.
Both water parks offer one of WDW's few bargains, a bucket of ice cream (called a "Sand Pail") with all the fixings at (I think) Sled Dog Expeditions (BB) or Happy Landings (TL). The bucket is not to be missed if you like soft serve ice cream; it is large enough to feed the six of us. Last time I checked it was $9.99.
A comparison of TL and BB is not complete without mentioning the music. Both water parks pipe in background music that adds to the experience. At BB, it tends to be a combination of California beach (e.g. Beach Boys) mixed with Christmas music, with an occasional yodeling song thrown in! At TL, it tends to be more Caribbean and beach songs. As people who only go a couple of times a year, we love it. However, I suspect it drives people who work there crazy!
