I personally think IoA is a bit overrated. It's great, and it's certainly got the best mix of rides of the lot, but it's lack of anything truly amazing means that it's not fixed in my memory all that well. Between the Superhero area, and Jurassic Park and what is now Harry Potter, what ....is there? Admittedly I went when it was BLOODY COLD and so avoided water areas, probably has a lot to do with it. There seems to be a hell of a lot of filler crap at that park. Again, on the other side of the park, between Harry Potter and the entrance... wtf is there?
Universal is worse. Simulator, simulator, simulator... yawn. In my head though, those parks are combined as one, and when you do that they collectively become the best theme park in Orlando because Revenge of the Mummy is INCREDIBLE. (That I've visited, only done Animal Kingdom of the Disney parks properly.)
I voted Sea World though. Kraken is one of my favourite coasters, combine that was what is effectively a giant world class zoo and aquarium and... Yeah, blew me away, really did. The exhibits there are amazing.
Oh and as for BGA, because it gets lumped in with them, it's overrated too. Especially compared to BGW. It's a horrible layout, it's a bit dry and baron, it's in a horrible area and it's themeing is a bit. I dunno. It almost reminded me of Pleasureland Southport. It's still bloody good there, but it just can't compete with Williamsburg, nor can it with Sea World or, tbh, any of the other major Florida parks. Montu, however. OMFG. <3