Vesper
Shake everything with ice and strain into a cocktail glass. Garnish with a lemon twist, and run it around the edge of the glass.
This is the martini ordered by James Bond in Ian Fleming's novel, Casino Royale. Bond tells the bartender, "Three measures of Gordon's, one of vodka, half a measure of Kina Lillet. Shake it very well until it's ice-cold, then add a large thin slice of lemon peel. Got it?"
Kina Lillet is no longer available, and is generally replaced with Lillet Blanc for a modern Vesper cocktail.
http://www.drinknation.com/drink/Vesper