SeaWorld and Aquatica for sure. That way you get two totally different experiences (theme park + water park) versus just water parks.
Blizzard Beach was, for us, disappointing. We hated the "snow/winter" theme. There was a lot of concrete and a lack of water park lushness. Definitely a one-and-done kind of attraction for our family.
Aquatica has the most amazing tubeless lazy river with a strong current (called Roa's Rapids) that is, without a doubt, the best water feature in any water park we've ever been to. Their interactive kids area is HUGE and puts the similar areas at BB & TL to shame. There are dual wave pools, big slides for thrill seekers, Commerson dolphins, a gorgeous sand beach, and a plethora of loungers and large blue umbrellas for shade which are free on a first-come, first served basis.
SeaWorld has spectacular shows, great rides, and some fabulous animal exhibits. Many of the rides (SkyTower, Antarctica, Turtle Trek, Wild Arctic) can be enjoyed by the whole family. Their coasters, Manta and Kraken, are fantastic for thrill seekers. Shamu's Happy Harbor offers some hands-on fun and and games for the younger guests. The animal feedings are super fun and a great way to learn about sea life. Its easily a place where you could spend two full days of your vacation.