Does the dead crab I saw on the beach last week count? If not, I'm really unsure when I last saw a sea creature.
I love dolphins because they are such cheerful-looking, playful creatures. I think I would like to experience being a dolphin or a whale. Or maybe I want to float around gently as a jellyfish.
Edited to add, now that I've read other responses . . . I also love otters! Sea turtles too. I have a big plush sea turtle on the back of my comfy chair. And manta rays are awesome! I really like them all!