If I had to pick a favorite park out of the four main ones, it would easily be Disney's Hollywood Studios (formerly MGM). I'm not someone who is all about present-day Hollywood and all the nonsense that goes on there, but I geek out HARD over the Golden Age of Hollywood vibe. If I wasn't such a feminist, sometimes I think it would be awesome to live in the 30s and 40s, and Hollywood Studios gives you a taste of that.
Not to mention, two of my favorite thrill rides -- the Tower of Terror and the Rock 'n' Roller Coaster -- are there. The Tower of Terror is a "Twilight Zone"-themed ride set in a 1930s hotel. You ascend to the top, get in the "elevator," watch some trippy "Twilight Zone" shit (which I LOVE), then drop 13 stories. It's basically the BEST. And the Rock 'n' Roller Coaster is an indoor 0-60 coaster with an all Aerosmith soundtrack. So fun. And aside from the thrill rides, there's the Great Movie Ride, set in a recreation of Grauman's Chinese Theater, which takes you through several classic movies.
Ugh, I'm making myself jealous of Jen's upcoming trip to Disney World.