Well, others have chimed in on Disney parks, and I agree with pretty much everything they say. I would also recommend Islands of Adventure, part of the Universal Resort. Last time my family went, I was 17, and my brothers were 13 and 10. The emphasis here is on thrill rides, so if that's something your family's into, I would definitely recommend a stop by IoA.
I would also recommend doing Disney last on your trip. In our experience, Universal and SeaWorld are a bit of a letdown after you've been to Disney World. They're definitely fun parks, but they just don't have the same magic atmosphere that Disney does.
Most of all, just remember to have fun and embrace the kid inside, no matter what your physical age!