Which beach in florida is best to go to?

Hey i'm from new jersey, and travelling to orlando florida for 5 days with my girlfriend. I want to go to the beach but which beach is the nicest and best to go to? I'm planning on renting jet skis, kayak , and surfboard . Also, my grl wants to be lame and see dolphins lol Any beaches in mind anyone? Also, which ones has the nicest clear looking water? Not that dirty green looking water