We were there this summer with 2 DS's age 7 and 6. They really enjoyed it. The following rides were at the top of their lists:
In IOA:
Spiderman
Jurassic Park
Everything in Seuss Landing
Pteranodon flyers (this one can get a long line quickly-try to hit it early-it's a short ride, kind of a kids roller coaster, but my boys absolutely loved it)
In US:
MIB
Jimmy Neutron
Shrek
Nick Studios (they do a pretend slime time live which my boys thought was just the best)
Jaws (I was surprised with this one, I had thought they'd be scared)
Also, while we were there, mid-day they had a jet ski stunt show going on. They do jumps and soak the crowd. My kids are still talking about this.
The one overwhelming thing my boys, and actually my whole family said they wanted to skip when we go again is Poseidon's Fury. It's probably worth seeing once if you have unlimited time, but if you need to pick and choose, I would suggest picking something else.
Have a great trip! Feel free to ask any questions!