#1 Sloop, #2 Galleon, #3 Frigate
But really it depends on what you are doing. Obviously if I want to get some where fast, or I'm on a quest to kill ships more often I'll take out the sloop. If I want to work on sailing or get some gold I'll take out my galleon.
Not really sure where the frigate fits, cause the only real advantage is a couple more crew. But I can have 10 on my galleon and 9 on my sloop so not sure why I even need the Frigate, but I'll have it soon anyways