We did the Dolphin Discovery at the park. For the price they charged and what you got to do it was a fair deal. The transportation both ways was included as well as the admission to the park.
We heard that the sea lion excursion was also very good. With that, you do get to swim with the sea lions. With the dolphins, you don't get to swim with them, but are in the water with them and get to touch/feed/play with them.