Typhoon Lagoon and Blizzard Beach both have a whole host of adult- and kiddie-attractions. They are both whole, complete water parks unto themselves. Each has a distinct theme, and each has its own rides and attractions.
Blizzard Beach is themed to be Florida’s first ski resort (due to a freak snowstorm) that melted when temperatures returned to normal. You will see references to snow, ice, Christmas time, skiing, sledding, etc.
Typhoon Lagoon is themed to be a tropical island paradise that was hit by a tropical storm. You will see a giant shipwreck on the mountain (Mount Mayday), remnants of a fruit-washing plant, etc.
Blizzard Beach boasts a huge body-slide called Summit Plummet. A near vertical drop will take you about 55mph on your way down – it even has a spedometer to measure your speed at the bottom, and in keeping with the theme, you take a chair lift to the top.
Typhoon Lagoon has a huge surf pool that produces 6 foot waves every 90 seconds. (In contrast, BB’s wave pool is calm “bobbing” waves, less than a foot high). Typhoon Lagoon is also the home of Shark Reef, where you can swim with salt water fish and other marine animals. It also is where you can find Crush & Gusher, a series of three water-coasters, with jets of water powerful enough to propell you up hill in addition to the normal descents of waterslides.
Both parks have a lazy-river that circles the entire park, and has multiple entrances and exits (so you can use it has a means of transportation). Both parks have a kiddie play area for the little ones. Both parks have both body slides and tube slides (though I think BB has more body and TL more tube).
I personally enjoy Typhoon Lagoon significantly more than Blizzard Beach. I love the surf pool, in which I could spend a few hours easily, and Crush & Gusher is a lot of fun if you get there early in the morning before the lines build. Plus Summit Plummet has a tendency to hurt my back, so I won’t do it more than once a day.
For more information, check out AllEars.net’s page on the two parks: Blizzard Beach and Typhoon Lagoon