Assuming this isn't just a hypothetical "anywhere in the world best hamfest", what area of the world are you interested in? Didn't you say you were going to be in Florida in December? You can't expect us to just remember that. Who knows why I think I do. I think the "best" fests are those close to home. What is your definition of best?
No, I might if there is a good up there. I am fine with any area. Best- big, many vendors, item for sale, eye candies and yeah so on...
What is your Call Sign? Where is your Location? Your Profile shows New Zealand. December is 6 months and 16 days away. Are you looking for Hamfests in the USA in December 2016? Are you asking where there are Hamfests in December 2016 in New Zealand and maybe Australia?
48 States I will guess. You can look online at the ARRL website and search Hamfest; by Date only, or search by State, etc. http://www.arrl.org/hamfests-and-conventions-calendar