Hello,
The slides are definitely better at Blizzard Beach so if you have thrill seekers go there! They are both well themed (BB is a ski resort and TL a tropical paradise) but my personal favourite is Typhoon Lagoon. I love the theme.
If you have children, both have great areas for kids. My DD's (at the time age 3 & 6) preferred the one at TL but both are excellent.
There are good slides at TL (just not as good as at BB), but the wave pool is fantastic. Also the Shark Reef is an interesting diversion for a bit.
So I'm in agreement with Chunkster!!
Karen