I love AK, I think you should definitely at least go once. We ended up going twice on our trip. Festival of the Lion King is a must see show, and it's tought to be a bug is so much fun. If you like the other 3d shows you'll definitely love this one. Of course Kilimanjaro Safari is also a must. It's a different experience each time because you don't know what animals will be out and where. So it's fun to look around and see what you can find, and sometimes they come up really close. Dinosaur is awesome if you like thrill rides, and of course there's Expedition Everest which will be opening around May.
Some of the things we didn't do on our 2001 trip we were very happy that we eventually did this trip. Rafiki's Planet Watch takes you to the Conservation Station, and we had a lot of fun there. I love petting animals, and they had all these animals roaming around that you could play with. We were there at least half an hour - hour. Also the Maharajah and Pangani Trails were really fun. They give you guides so you know what you're looking at. My favorites would have to be the gorillas, they were really funny.
So basically you should visit at least once to see what you think. It really is a beautiful park and even just walking into the park through the Oasis, it's fun to just stop and see all the animals around there.