I don't know why people call Epcot boring... my family loves it (my youngest is nine).
It's the best place to meet the classic characters (Mickey, Minny, Donald, Goofy, Pluto) as they are all together under one air-conditioned roof with only 1 line to see all of them, so if you want pics it is 1-stop shopping (I am in my 40s but still love to meet them).
Spaceship Earth (in the giant geosphere) is interesting and the computerized cartoon they put you in at the end is a lot of fun to do. Then you empty into a room where you get to play with gadgets, which is always fun.
Innovations East & West (different things in each) have lots of crazy gadgets and hands-on technology things to do. One game lets you "invent" your own roller-coaster ride and then you get on this futuristic virutal reality contraption to take the ride you programmed. How cool is that?
Next to Mission Space is Test Track, which is really fun if you like really fast driving! No simulators-- you actually go. I could do that one again and again!
There is a cool little boat ride in the same building as Soarin that brings you through these space-age green houses where they grow food for one of the restaurants in Disney. And there is a Lion King environmental movie in the building that has absolutely amazing images. Those can keep you busy while you're waiting for those Soarin fast passes to go.
The pavillions are so cool... get the Kim Possible game phones before entering the world show case... even if you're grown, it's fun. It gives you a mystery, you push buttons, it's interactive and little things in the park pop up as you are walking around while doing it. It's cool, there are little secrets everywhere.
The shops in the world showcase are great and each "country" has a nice place to sit and soak up some atmosphere (I love Italy and China especially), there are lots of shows and films too if you're interested in traveling or history.
In Norway there is a fun indoor viking boat ride and in Mexico there is a funny boat ride featuring the 3 Caballeros with georgous scenery.
I love to stop and see the "Beatles" (British Invasion), they are so great if you like 60's and 70's British rock in such a quaint little courtyard, and I like the Celtic rock band while I stop for fish & chips for lunch. Every pavillion has some kind of entertainment that is interesting, some have street shows... like last week we went by Paris and some waiters come out and begin stacking chairs and doing handstands, the guy must have stacked 10 chairs one on top of the other climbing higher and higher. I also got to see some woman from Japan make amazing sculpted candy pops in a few minutes.
There are just so many nooks and crannies in the world showcase, and there are boats if you don't want to walk as much.
Illuminations is one of the best night time shows in all of Disney, it's spectacular.