As others have already said, spring for the Park Hoppers. They'll allow you the flexibility toA) not have to spend the entire day at a park where you have a reservation.B) allow you to supplement some of the parks where you might not need the whole day, andC) properly take advantage of EMH. Its great to be there during the EMH, but during normal park hours whichever park has EMH that day will be insanely busy. For morning EMH get there at 8 then about 11 or so head out to whichever park had EMH the previous day. For evening EMH just try to get there a little bit before regular park close.A little about FastpassThere really aren't that many attractions that require Fastpass, though each park has at least one ride where it's imperative that you get there at park open and send one person immediately for Fastpasses.Essential FP (go get them first thing in the morning)MK: Space MountainEpcot: Soarin'Studios: Toy StoryAK: SafariRecommended FPMK: Splash, Thunder, Pan, PoohEpcot: Test Track, Mission SpaceStudios: Tower, RnRC, Star Tours (when it reopens in May)AK: EverestUnnecessary FPMK: Jungle Cruise, BuzzEpcot: Maelstrom, EOStudios: noneAK: Dinosaur, Kali, Primeval Whirl