You have 6 days pass. As this is your first trip, I suspect you will not need to hop from park to park : a day at each park will let you enjoy everything you want, and you then have two full days to do what you didn't find the time to do the first time.

Magic Kingdom (MK) is the classic Disney park, very close to what you experienced at Disneyland, but not quite the same. It's quite big, and full of nice dark rides. Nearly every ride there is a classic, and that's where you'll find Big Thunder Mountain, Splash Mountain and Space Mountain. You won't want to miss Haunted Manor (not scary) and Pirates of the Carribean (with Johnny Depp !) Newest show there is Monster Inc Comedy Club, which is a great interactive experience, very funny, in Tomorrowland. Some here think it takes two days to do everything, but with a clever use of Fastpass, you can do most in one day. This is a beautiful park to just walk in, with a very lush landscape. The nightshow is a firework named Wishes, and is great.

Epcot is another classic park, including future world (a land about discovery and science) and World Showcase (a land about countries around the world). Big rides there are all in Future World and include Test Track, Mission : Space and Soarin'. You'll want to make some time to discover the differnet countries and talk to the Cast Members for your report : they come from all these countries. Minor rides can be found in the World Showcase, they are nice and you should experiment some of them. The nightshow is a show with water, fire, video and fireworks named IllumiNATIONS and should not be missed.

Disney's Hollywood Studios (DHS) once was a working studio, but no more. Big rides there include Tower of Terror (free fall), Rock and Roller Coaster and Toy Story Midway Mania. There are lots of shows there, and you should make some time to experience som (like Beauty and the Beast, and Indiana Jones). This is my least favorite park. The nightshow is a show with fire, water and video, and is also my least favorite, but shoukd be seen at least once.

Animal Kindom (AK) is a park about animals, but it is not a zoo. Big rides there include Kilimanjaro Safari (a safari) and Expedition Everest (coaster). Nemo is a GREAT muscial, and my personal favorite on property. Don't miss it ! You should make some time to walk around : there are animals everywhere, and the trails give you great opportunities to see them from up close. Some people think this is a half day park, mostly because there are not a lot of rides. But if you take the time to discover all the animals, you will spend the day there. There is no nightshow (hey, animals need to sleep !)

If you want to get away from the parks on your last two days, you could enjoy a waterpark (there are two : Typhoon Lagoon and Blizzard Beach), play minigolf (There are two : one near blizzard beach, and another near the Boardwalk), shop around Downtown Disney, or enjoy a giant arcade with tons of videogames at DisneyQuest (in Downtown Disney).

Now, this is a lot of info, so don't hesitate to ask questions and we will all gladly answer them !

All this reflects only my personal opinion, and I'm sure some other posters will disagree with some of my opinions ! This is what's great with WDW : we all like different things, and we still all love it !