We recently got back from our 5th time at WDW and still haven't done everything. We try to eat at new places each trip. Here are some of my favorites!
MK
Place to eat:Cosmic Rays(we liked the ribs) Crystal Palace for Breakfast...Pooh and Friends are there, Terrace Noodle Station,
Rides

irates of the Caribbean, Dumbo, Alladin, Peter Pan, Small World, Mickey's Philharmagic, The Little Mermaid...The Astro Orbitor, The Haunted Mansion
Shows: catch the stage show at the Castle (my dh and I had teary eyes the first time we saw it) Wishes fireworks and both the daytime and Spectromagic parades are a must. TIP:when there aren't any seats left on Main Street..there is always one in front of the garbage cans lol!
AK
Place to Eat: Flame Tree Barbecue it's awesome! Sanaa at AK Lodge
Breakfast: Ohana's at Poly
Rides: A Bugs Life(my daughter is petrified of this ride lol) Kilimanjaro safari (it was raining our first time and we didn't know it wasn't part of the ride lol)
Shows:Nemo, The Lion King
Epcot: The whole World Showcase is a Must see!
Food Favorites: the churro from Mexico, Frances' Grand Marnier Slush, Japan dinner at Teppan Edo, breakfast at Akershus with the Princesses
Rides: Test Track(make sure you fast pass it) Finding Nemo
Fireworks were the best I had ever seen til they shortened them(steak out your place up to 45 minutes before)
Hollywood Studios:
Food Favorites: the Turkey Leg, Prime Time Cafe
Rides: Tower of Terror (I'm a chicken)
Shows: Indiana Jones, Muppet's 3D
Downtown Disney: The
Lego exhibits all over.(there's a lego family and other things scattered throughout DTD, The stores are awesome and each are different themed. Goofys has the coolest looking apples I've ever seen!
You can get free maps from the disney.com site so you know what you want to do. If you have kids take them back to the hotel midday for a nap. Stay hydrated and wear sunscreen even if it's overcast!