Ingredients: gin, lime, sugar syrup.
Shake, with ice, one jigger of gin, a third of a jigger of sugar syrup, and the juice of one lime. Pour into a chilled cocktail glass. For extra fun, frost the glass with sugar by rubbing the rim with a lime wedge and dipping repeatedly into a bowl of sugar.
The traditional recipe calls for a bottled, sweetened lime juice such as Rose's, but I prefer the fresh lime. With vodka this is a Vodka Gimlet and so the above is often called a Gin Gimlet for clarity. Try adding a bit of your favourite liqueur.