Compare to other water parks...Disney water parks are awesome. Probably some of the best theming on property.
Compared to each-other? It's been a few years, but blizzard beach is much more of a "thrill-park" type water park. The rides are long and fast. Typhoon Lagoon the slides are not as big in general, and they have a really neat pool with fish and manta rays and sharks that you can snorkle across. (Freaked my DW out, though, she couldn't keep her head down to watch the fish.) They've added Crush N Gusher since we've been there, which is a "Water coaster", but if you are looking more laid back slides, that's the park for you. They're both pretty awesome, though.
SkierPete