4 c Sky vodka
2 c Malibu rum
2 c Stoli Vanil vodka
1/4 c sugar.
First, remove the skin from the pineapple, and cut it into wedges, 1/2 inch thick. Place the pineapple wedges in a large pitcher. I like to use a sun tea pitcher, because it's got a little spout on the bottom.
Next, pour the sugar and alcohol over the pineapple, and let it sit for at least two days. The longer it sits, the smoother the flavor.
To serve, pour about 4 oz into a shaker of ice, and shake until nice and cold. Serve in a martini glass, and garnish with a wedge of pineapple, either fresh, or from the martini pitcher. Remember, the pineapples in the martini pitcher have been sitting in booze for days, so they're pretty much entirely alcohol.
Pineapple martinis are also great when mixed with orange juice, if you're looking for a reminder of your last tropical vacation.
This is my take on a recipe I originally found here, for Roy's Hawaiian Martinis.