Caye Caulker of Bannister Island?

If you're looking to vacation independently in Belize (instead of on some kind of cruise ship), Caye Caulker is a much better destination than Bannister Island.

Bannister Island mostly caters to short term visitors on cruise ships and doesn't have as much of a local Belize feel.

Caye Caulker has access to all the activities you might want to do and has great local restaurants with fresh caught sea food.  It feels a world away from the mainland and taking a ferry from Belize City is a great part of the adventure.