Wray and Nephew Rum is an over proof alcohol that is a favourite of my friends who grew up in Jamaica. It is available in 750 ml bottles at the Montego Bay airport duty-free store for under $10.
Coconut rum is another good choice at the duty-free store. I have picked up a bottle of Coconut Rum Finzi it goes over well at my summer barbecues. I also use it to marinade the fish for my fish tacos as it gives a nice island taste to the dish.
Blue mountain Coffee beans and jerk seasoning for cooking are also a favourite items for flight attendants to bring back from Jamaica.