I went to Discovery Cove in Orlando 5 years ago. It was an amazing experience. Of course, I would have liked the dolphin interaction to be longer, but they have fabulous customer service, and there is a ton of things to do when you aren't with the dolphins -- snorkling, lazy river, swimming, etc. The food was phenomenal and was included in the admission. I highly recommend it. They only allow a certain number of people into the park each day, so it wasn't crowded at all.
If you go to Discovery Cove, make sure you get there as early as possible in the morning, because the sign up for dolphin time was first come first serve. We took a shuttle and were late, so we ended up with the very last time slot.