My family and I were there in December and the kids, naturally, want to go back ASAFP. It was the first time my wife had been there so she really wants to go back, too. Once the kids are older they'll be more willing to go on the "scarier" rides. My oldest, seven years old now, loved everything we threw at him but my five year old didn't like Dinosaur, Space Mountain or Test Track. But the little trooper did 'em all! Once.
Yeah, they never do get bored there, until they hit like 11 or so, I've heard.
Speaking of Test Track, we headed over there to get a Speed Pass but they were all out for the day and the wait was 2 hours so we were just going to find something else to do. Charlotte, one of the Test Track employees, had different plans, though. She asked if we wanted to go on the ride and we said we'd like to but the wait is too long. She told us to follow her into an Employees Only door where we were on a catwalk over the ride that lead straight to the front of the line. Total wait time - 2 minutes.

👍
Got that once for Haunted Mansion; it's rare, although we got a little tour to go with it, since the wife and I had silly buttons saying we were on our honeymoon. Lots of neat stories to explain the ghosts and stuff (some were modeled after founders/employees).
My wife was also bumped off of the Dumbo ride because the tool behind her cut in line...
It's one of the worst waits in the park, for some reason. Some jackass cut the line right in front of Bailey and I, but they give you a little card just before you enter, since it's easy to cut the line for some reason. So this guy holds up the ride for 3-4 minutes while he flusters around so I shouted at him until he got out. Tough crap buddy, we waited 45 minutes while your happy ass was eating a turkey leg.
By the same token, you never notice it being cleaned, yet it has to be a constant operation.
The people in the white coats with pastel colors are everywhere, all the time. Sweeping, cleaning, picking up, sweeping, cleaning...they just make no noise and never stand around too long. You start to realize why you paid $80 a ticket when you realize how many support personnel are doing things in the background (well that, and the fact there's three actual steam locomotives running all day long on a narrow-gauge track circulating the park...that can't be cheap).
Take time to visit some of the better restaurants, not just the fast food stuff they do (although they do it well.) In EPCOT, the Chinese restaurant (Nine Dragons) is excellent, and the restaurant in The Living Seas (Coral Reef) is incredible, although more expensive.
Disney food is a bit of a bait-and-switch: You can get ripped off for the cheap stuff, and get some disappointing food, or make reservations for the slightly nicer stuff and only pay a little bit more in comparison, and get good service to boot.
The catch is, you usually have to make reservations at least one week in advance. Forget about just casually showing up and grabbing a table; some places (like eating at Cinderella's Castle) require a reservation made
exactly 90 days before the day you're visiting. The prime rib was really good though, and view is nice. Very quiet inside, but you realize there's only seating for about 60-70 people.
The Japan Inn was okay, although prices were actually pretty fair. Where else can you eat out of a toy passenger aircraft?
Vicotria and Alberts is really hoity-toity. Had to do that once; no kids, then. Didn't see any there, either.
If you've got to eat the cheap stuff, then I recommend Pincochio Village Haus in Fantasyland, as the food isn't burgers and fires. Make sure you eat at those places (like Cosmic Rays, or the Electric Umbrella, for example) at off-peak times (before 11:45am, after 3:00pm) or it's so noisy and swamped that you wish you weren't a real boy.
Make a reservation at Tony's at the Magic Kingdom just around sundown, so you can watch the parade of lighted-stuff (Spectramagic, for example) at just the right time, if you request a outdoor table. It takes a little work to find out the approximate sunset times and parade schedules, but you won't regret it. The priceless part is listening to all the hangers-on ask if there's any other tables left...
You'll have several nights, so you can see all of the night shows: the Magic Kingdom "Wishes" fireworks, the EPCOT Illuminations laser and fireworks show, and the Fantasmic show at Holywood Studios. Fantasmic is my favorite of those.
That walk to and from Fantasmic seating ought to come with a Segway, though.
Mad Tea Party and Pirates of the Carribean (it's nice and cold inside), do the Space/Thunder Mountain rides and Fast Pass your rides judiciously.
Test Track is neat. You can ride Single Rider if you're a loser or your wife is pregnant and your daughter fell asleep in her stroller (line = 2 minutes).
Soarin' and Mission: Space are worth the fear of nausea. The pavilions are so-so, although the little French bakery shouldn't be missed. Norway has the coolest ride and the supporting movie is very-1988.
Animal Kingdom has to be done early. Wake up early and get there early. It's rather boring after 11am, as the animals are too tired to stay in the sun, and refuse to be photographed.
People watch when you're bored (someone always looks like they just fell off the turnip truck or beat with the Weirdo Stick) or look for Hidden Mickeys.
Go see the Magic Kingdom be opened. Go see it's a small world and feel good about how truly petty we all are in reality. Go hum a silly Disney tune that's stuck in your head. Quote something really obscure from Toy Story. Thumb your nose and jeer at anyone wearing a political T-shirt. Pretend for a day and forget about bills, and death (save the Haunted Mansion), and taxes, and debt, and trolls, and trivial meaninglessness of our personal lives compared to entire scope of the universe and have fun for a moment or two while cramming a pretzel in your mouth and sucking down a soda with too much ice in it and pointing at something.
And by all means, go see the Lights, Camera, Action! thing at Hollywood Studios.