Sea World has also just opened a new shopping and dining area, "Waterfront".
OK, here are my 'must-do' attractions in the parks you've mentioned:
<b>MK</b> - Jungle Cruise, Pirates of the Caribbean, Splash Mountain, Big Thunder Mountain, The Haunted Mansion, Peter Pan's Flight, It's a Small World (I love nostalgia and Walt designed this himself for the 1964 World's Fair), Space Mountain, Buzz Lightyear and, if it's open when you go, Carousel of Progress (again, Walt designed it for the 1964 World's Fair and it is probably my favourite ride in all the Disney parks).
I'm not overly keen on parades, or at least, I don't like all the argy bargy and hanging around which seem unavoidable. However, Spectromagic is stunning and, if you're there for that you should also factor in Fantasy in the Sky fireworks, which are usually shown during evenings when Spectro is showing. The current afternoon parade, Share a Dream Come True, is lacking in something in my view.
For something different, catch a launch over to Wilderness Lodge for lunch (Whispering Canyon Cafe), or get on the resort monorail and try one of the restaurants at Grand Floridian, Polynesian or the Contemporary. You need to be careful when selecting as they're not all open for lunch.
<b>Epcot</b> - this is my favourite park, although the World Showcase part could go either way with your kids at the ages they are. It might be worth checking out the 'Kid Stops' - they undertake activities at the pavilions and get a 'passport' stamped.
Future World - Spaceship Earth, Ellen's Energy Adventure (although be aware that this is a long ride - about 45 minutes), Cranium Command, Test Track, Living with the Land (I love it, but it's not for everyone), Food Rocks, Honey, I Shrunk the Audience. Innoventions East and West are also worth a look and your kids (and you) will love Ice Station Cool. You get to sample free Coca-Cola fizzy drinks from around the World - some more palatable than others!
World Showcase - There are rides in both Mexico and Norway, so it's probably best to go anti-clockwise, starting at Mexico. The audioanimatronics show at USA is impressive, but long (30 minutes). I've seen it 3 or 4 times and haven't managed to stay awake for the entire show, yet! There are also shows in China, France and Canada (I'd say that O Canada is the best of them), but they might be a bit boring for children.
There are lots of places to eat in Epcot, but if you're looking for something different, stroll across to the BoardWalk from the International Gateway in World Showcase, especially if you're there during the evening.
The best parade WDW has ever staged, in my view, has just come to an end (Tapestry of Nations/Dreams) and no replacement has been announced to my knowledge. However, whatever else you do during your time there, be sure to catch IllumiNations.
<b>AK</b> - It's Tough to be a Bug, Kilimanjaro Safaris, Kali River Rapids, Maharajah Jungle Trek (if you like Tigers), Dinosaur. This is a beautiful park and very much one for chilling out and taking it all in.
The food offerings here are dire, IMHO, with the exception of the Rainforest Cafe. It gets knocked a lot, but I really don't quite understand why. It can be a little bit expensive, but the food is fresh, the portions large and the place itself has to be seen to be believed.
Mickey's Jammin' Jungle Parade is excellent and there are lots of good spots along the route. Our favourite is outside the restrooms in Africa, opposite the entrance to the Tusker House restaurant. There is a walled flower bed (or something similar). You can sit on it and no-one can stand in front of you. This is right where the parade starts and, if you want to, you can stay there and see it again, as it passes the same way on the return route.
<b>MGM</b> - Tower of Terror, Rock 'n' Roller Coaster, Beauty and the Beast (if you have girls), Voyage of the Little Mermaid (ditto), The Magic of Disney Animation (if you are there during a week day between 9am and 5pm, i.e. when you can actually see animators working), Walt Disney: One Man's Dream (if you like history/nostalgia), Who Want's to Be a Millionaire, the Backlot Tour, Muppets 3D. Star Tours, Indiana Jones and, if it's open, The Great Movie Ride.
The restaurants here are all quite good. We tried the 50s Prime Time Cafe for the first time ever last October and we were pleasantly surprised - a real riot!
I've had several abortive attempts at seeing the Movie Stars and their Cars parade, so I can't help you with that.
<b>Universal Studios</b> - Terminator 2 3D, ET, Back to the Future, Men in Black, Jaws (not my favourite, but you've got to do it once), ditto Earthquake and Twister, The Wild, Wild, Wild West Stunt Show, Jimmy Neutron. And you lucky, lucky things - you'll get to see Shrek 4D. I haven't seen it yet, but I promise you it will be outstanding!
<b>IoA</b> - Spiderman, Hulk, Spiderman, Doctor Doom if your kids are brave (you wouldn't catch me on it, but my 2 daughters claim to love it), Spiderman, Popeye and Bluto's Bilge Rat Barges (and also spend some time on Me Ship, The Olive blasting other riders with water!), I didn't like Dudley Doo-Right's Ripsaw Falls and I haven't plucked up the courage to do Jurassic Park, but I guess they're probably on most people's 'must-do' lists, Poseidon's Fury, The Mystic Fountain (not a ride, but either let your kids interact or watch other vicitims!), The Eighth Voyage of Sinbad, Duelling Dragon and all the rides in Seuss Landing. Oh, and Spiderman.
At both US and IoA, I'd be tempted to eat at CityWalk. Hard Rock Cafe is my favourite of all the offerings there. CityWalk and Downtown Disney are both great during the daytime, but they really come alive during the evening and it is probably worth trying to factor in some time at at least one of them.
I can't swim, so all my time at Water Parks is spent chilling out, and I haven't been to Busch Gardens since 1996, so I can't add much there.
Above all, relax and have fun. It can be so easy to try to do too much and you'll just end up coming home feeling you missed out on something. Avoid Early Entry days (unless you're staying onsite) and make a pact not to argue, no matter what.
