When cherries go on sale, I always whip up at least one batch of brandied cocktail cherries. Find the complete tutorial on Instructables. The recipe is super simple:
1 cup hot water
1/2 cup sugar
1 cup brandy
Whole spices like cinnamon, star anise (optional)
These cherries will keep in the fridge for several weeks, and only get better as they soak up the alcohol-sugar mixture, and besides cocktail garnishes, they make a great ice cream topping along with the liquid from the jar.