I enjoy aspects of both parks.
The kid zone at Blizzard Beach where they cross the ice patches while hanging onto the rope net is really cool, as well as the zip line. My little girl loves to do both. Also, it actually has downhill slides that you can ride face first. Not many parks will let you do that.
Nothing can top the wave pool at Typhoon Lagoon. The Crush N Gusher is awesome, and their lazy river is deeper than Blizard Beach. The first time I got in the lazy river at BB, I scraped my knees all up on the bottom of the river while I was dangling from an intertube. Don't have that problem at TL.
We have been to TL way more than BB, so my little girl wanted to go to BB for her b'day next month. Unfortunately, it will be down for maintenance by then.