Do the one where you swim with them, not the other one that allows you to stand in the water with them. It's more expensive, but its a once in a lifetime thing & worth every penny.
When we went, we were on vacation for a week in Nassau so it was like $125 or $150. But this is going back about 7 years ago or so.
Best part was you swim out a ways (you are in a lagoon & wear a life jacket) and do a Superman position - hands out, feet together pointed downwards.
Two dolphins come up behind you, push you on your heels with their noses & send you flying across the lagoon in the water. It's awesome & right at that point do you have a true sense of how powerful these creatures are!!