I live in Central Florida and there are lots of choices, depending on your interests.
I think Disney World is definitely worthwhile - it has the Magic Kingdom, Epcot, & Hollywood Studios right in one place and if you buy a park hopper ticket you can jump around from one to another as you like. My personal favorite of those is Epcot. The hotels are great to see, even if you don't stay there. The Wilderness Lodge, Animal Kingdom Lodge, Polynesian, and Grand Floridian are really something to see. There is also a unique shopping and restaurant area - Downtown Disney. You could actually spend four days just the Disney area and not see everything.
Universal is very popular, but I've never been there. It has lots of thrill rides, but I believe that I have outgrown most of those. My body doesn't like the abuse anymore :(.
Sea World is entertaining, with lots of shows and interaction with sea life, but as has been stated by others, there are a number of Sea Worlds around the country.
There are also some neat areas that are less well known. You might want to check out Wekiva Springs, Bok Tower, or Leu Gardens if you like relaxing nature type settings.
If you are in Orlando, you are not too far from Tampa. Tampa has Busch Gardens, Rays baseball games, and Seminole Hard Rock Casino.
Hope you enjoy your visit to the area!