The Aviation.  This is now my favorite.  Gin, maraschino cherry liquer, lemon juice (sometimes lime) and... creme de violette.   The color of the drink is of the sky.  
- shot of gin (I like it with lots of botanicals, but that's me)
 
- tsp of the creme de violette
 
- half ounce (third of a shot) of the maraschino
 
- half a shot of lemon juice
 
Or, make 3 at once
- 3 shots of gin
 
- half shot of the creme de violette
 
- shot of the maraschino liquer
 
- shot and a half of lemon juice
 
Pour over ice in a shaker, shake, strain over chilled cocktail glass, garnish with a cherry or twist of lemon peel.  Mmmmm.