I would concentrate on Waterworld's unique attractions. Voyage to the Center of the Earth and Lost River of the Pharaohs are more like dark ride float-throughs than typical water rides. You don't want to miss those, even if the lines are long. You probably won't want to miss Screamin' Mimi. It looks kind of like a rampage but the sled actually has wheels on it and it lands in the water. It is pretty much a roller coaster into a splash pool. I would also recommend Ragin' Colorado, and the other tube shoots that have that "homemade" look. They have lots of other typical water park attractions that while enjoyable, can also be found at other parks. If you've been to a lot of water parks you will recognize many of the typical attractions and may not want to wait in long lines for those, concentrating instead on the unique stuff. The speed bowls usually have very long and slow moving lines, and you can find speed bowls at other parks--I would skip them.
Lagoon is a nice park with a classic woodie. If you are a Schwarzkopf fan it is worth going just to see the beautifully restored Jet Star 2, and to witness Fire Dragon in action. When I was there they were running two trains, and their dispatches put Dorney's Laser to shame. The ride is still smooth, fast and intense, and runs just the way Anton intended. I also thought the mouse and spinning coaster were very good. Unfortunately I don't think Wicked will be up and running by Memorial Day weekend.
