Off-season (if there is such a thing), it is great: lots of cool shows with amazing animals and their almost-as-amazing trainers.
Don't miss the sea lion show if you have kids -- it is just so darn funny, you almost pee!
The killer whale show is another MUST-SEE -- five minutes after the show, I was still transfixed in my seat, dreaming about sticking a killer whale in my bathtub of my third floor apartment!
Flipper -- how can one go to Sea World and NOT see Flipper? Go see the dolphins -- they are amazing creatures with a most wonderful playful personality!