Here are my top picks:
Waterpark of America at the Radisson, Bloomington. Hands-down, the best option if you have teens. This park claims to be the biggest in Minnesota. As is often said, though, size doesn't matter. Here it's the variety and openess--a lack of claustrophia that plagues many water parks. I also love its Minnesota theme, especially the replica of Split Rock Lighthouse that serves as the centerpiece.
Unless they're maxed out with guests (a possibility during long holiday weekends), they do take day visitors. That can help with the family budget.
An obvious bonus: Shuttles to Mall of America. Unexpected bonus: Watching planes take off from the nearby Minneapolis-St. Paul Airport every few minutes. Watch from the water park's second-floor balcony.
Best pick for a vacation area:
Paul Bunyan Water Park, Baxter. You can find a water park on either side of Highway 371 just north of Brainerd-Baxter's commercial strip. The other one, a Holiday Inn Express with its Three Bears Lodge is fine, but I favor The Lodge at Brainerd Lakes. There are bright red hallways and cozy log-themed rooms with fun titles that will appeal to kids. I like the waterpark's Minnesota theme here, too. It has some playful touches, like Paul's giant socks hanging from a clothesline. For kids, the caveat will be the slides with programable holographic special effects. You can slip past butterflies, sharks or get the impression you're busting through a brick wall at the bottom. The onsite Rockwoods Grill and Backwater Bar also has good comfort food options, including Tater Tot hotdish, pot pie and rotisserie chicken.
Best for overall on-site activities:
Arrowwood Resort & Conference Center, Alexandria.
I'm going to be honest. The state's very first waterpark, The Big Splash, is looking faded and a bit tattered. That said, I'd still recommend Arrowwood. Why? It's the best place to enjoy both the fake tropics and have true winter fun. The resort offers snowmobiling, ice skating, ice-fishing and sledding right on site (they even provide sleds), plus other kid-friendly activities. If your kids are old enough for real swimming or in the been-there, done-that camp for waterpark amenities, there is a large indoor pool, too. (I'd have to say waterparks make me miss good old swimming.) Word of advice: Arrowwood's new townhomes are lovely, but you'll want to stay in the main resort rooms or suites for easy waterpark or pool access. You can opt for a full or partial kitchen, too, which is worth it when you have tired kids, wet hair, no make-up and can't stomach any more water park snack food.
Biggest, best waterparks
Crave someplace bigger with more bells and whistles? Check out the four best resorts in Wisconsin Dells.