Musts:
Pina colada at Victoria House
Conch fritters at Rico's
Chicken falafal wrap at Ali Baba's
Huevos Rancheros at Manuels
Snook at Blue Water Grill
Sushi at Blue Water Grill (yes, sushi - it's amazing)
Sunday BBQ at BC's
Fresh pineapple from any street vendor
Breakfast burrito at Estelle's
Beach BBQ (fishing in the a.m., beach bbq, snorkle in afternoon)
Margarita at Cannibals
Lady Sharon cruise to Caye Caulker
Midnight skinny dip in the ocean
Barefoot stroll on front street
Homemade banana bread sold by locals and in some markets
Meat pies from Celi's
Surf & turf at Capricorn
Panty Ripper at Rico's
Dennis Wolfe wherever he's performing
Fresh fish/shrimp/lobster straight off the boat (if you have a place to cook it)

Sheesh, I could go on and on...