I have to say the Number one park in my opinion is Magic Kingdom. Someone tell me you dont get a thrill or chill walking down mainstreet, listening to the old music, everyone's smiling, and you see the occasional giant mouse running around in pants. Now, I live right in the heart of Orlando, and for the majority of my school, there favorite parks are IOA and AK (I havent figured out the last one yet)...When IOA opened down here, everyone was in shock. It was a greatly themed park, with 2 Good coasters, great water rides, and a couple, almost Disney quality, dark rides. I have been to IOA 4 times (im a self confessed Uni hater), and Im bored with it. The same experience every time, no magic, No inside Jokes to look for, No hidden Mickeys, NO CM'S THAT GO OUT OF THERE WAY TO MAKE IT MORE ENJOYABLE, and, for me, that doesnt thrill me, but rather turn me off to the park completely. Magic Kingdom has great thrilling attractions, plus Magic. Disney wouldnt be anything without that 5 letter word.
Now for the Mission:SPACE thing. Wait til some of the shows come out after October, and Mission:SPACE will be all over them. This links into the paragraph above, but MS is an experience never felt before in a Theme Park type junction. Its a new attraction, that I think, will do a total 180 degree spin for the better for Disney, Epcot, and Thrill rides in particular. Eisner let the budget go high, and look what resulted, maybe that will change there minds about future projects.