The unique features of regional rums are one of the keys to tiki drinks. And one of the most important varieties is Jamaican rum, with its hefty dose of funk from the addition of dunder to the fermenting molasses mash. Dunder is the leftovers from previous distillations, which is often allowed to sit outside in open pits, where wild yeasts continue to colonize the goo, adding all sorts of unique esters and other volatile compounds that are the key to true Jamaican rum.
One of the best ways to showcase this feature of Jamaican rum is the Montego Bay cocktail:
1.5 oz Jamaican rum
0.5 oz grapefruit juice
0.5 oz lime juice
0.75 oz honey syrup
0.25 oz allspice dram
1 dash Herbsaint
2 dashes Angostura bitters
Combine all ingredients, add a small handful of cracked ice, blend for five seconds and pour unstrained into a chilled glass with more cracked ice.
As I noted, this is really a showcase for the rum. As per Oh Gosh!, I've got to agree that this is basically made for Smith & Cross. It is basically Jamaican rum in its purest and most intense form (though you might be able to say the same for J. Wray). However, until you've acclimated yourself to its particular brand of goodness, you might not want to go for a full measure of S&C in this drink (especially if you want to remain standing). I find that cutting it a bit with Appleton V/X can be a good way to dial back the flavors and proof just a bit, without losing that essential Jamaican character. To account for the more robust character of the Smith & Cross, the recipe above bumps up the amount of honey syrup, allspice dram, pastis and bitters to keep them from being lost amid the funk. So it's all a bit of a punch in the face of flavor, but more than worth it.
For a relatively short list of ingredients (for a tiki drink), this one is delightfully complex. The rum forms the core of the drink, especially if you're using Smith & Cross. Around that core is wrapped the fruit flavors of the lime and grapefruit, which bring sourness and bitterness that is counterbalanced by the smooth honey sweetness. Finally, the dunder funk of the rum is backed up by the spicy notes from the allspice dram and the Don the Beachcomber one-two punch of Angostura bitters and Pernod.