Let's start off with the best first - now, I have only been to a handful of theme parks, but Cedar Point in Sandusky Ohio has to be the best one. Nothing else I've been to comes close. Oh, but some may argue that some parks have better "themeing". Who cares? There are so many great rides there. The Raptor, the 200 some foot Magnum (this is the best ride to waiting in line ratio in the whole park), 300 some foot Millennium Force, and the 400 some foot Dragster (simulated plane crash), plus like 12 other coasters and lots of other rides.
I'm not going to go on about the park - I just really wanted to write about how shitty of a theme park Disney World is. I went when I was nine, and even I knew Disney was a rip-off. It isn't magical. The rides are boring and you have to wait in line forever in each one. You have to wait everywhere. It took our family three tries to even get on the tram to take us from the parking lot to the main gate, since every other family would push you out of the way (since they tried waiting like you did, but it didn't work). They even have pseudo-educational rides. But the worst part is how fucking expensive the place is. It cost at least $250 just for tickets for five back then - I'm sure it is more now. Every piece of Disney food, every piece of Disney merchandise is WAY overpriced. Everyone is singing happy songs. Marketing ploys everywhere. It's like we paid money to watch commercials.
I think that's another reason why I like Cedar Point. It doesn't sell out. Of course theme parks are notorious for price gouging and marketing useless products, but Cedar Point's attempts at this are reasonable. They don't name rides after Batman like at Six Flags - they don't sell you a crap load of Mickey Mouse pencils and Donald Duck sweaters. The only thing Cedar Point advertises is Cedar Point - not some third party conglomerate.
I can only imagine the horror that is Euro Disney.