Both are great, and might I add if you have the time - Busch Gardens in Tampa - I think it trumps Animal Kingdom in so many ways! You can get a bus from Sea World (not positve of the cost - I think $10/pp)
DD and I have lived here for almost three years, and this year I added BG to our SW passes, and boy am I glad I did.... we were there twice last weekend, and if it was not almost 100 miles from home, I would be there again. It's got animals (saw many more closer up then ever at AK), and SEVEN - count them SEVEN roller coasters if you like thrill rides.
I have Sea World and Busch Garden photos "gallery" if you click on "My Pictures" below - of course I have AK too!