Gins best for a Vesper

The drink was invented and named by secret agent James Bond in the 1953 novel Casino Royale.
 
“A dry martini,” [Bond] said. “One. In a deep champagne goblet.”
“Oui, monsieur.”
“Just a moment. 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?”
“Certainly, monsieur.” The barman seemed pleased with the idea.
“Gosh, that’s certainly a drink,” said Leiter.
Bond laughed. “When I’m…er…concentrating,” he explained, “I never have more than one drink before dinner. But I do like that one to be large and very strong and very cold and very well-made. I hate small portions of anything, particularly when they taste bad. This drink’s my own invention. I’m going to patent it when I can think of a good name.”

 
—Ian Fleming, Casino Royale, Chapter 7, “Rouge et Noir’
 
Bond in the next chapter, “Pink Lights and Champagne”, names it the Vesper. At the time of his first introduction to the beautiful Vesper Lynd.
 
Kina Lillet is no longer available, so many will use Lillet Blanc/Blonde instead.
 
Esquire printed the following update of the recipe in 2006:
 
“Shake (if you must) with plenty of cracked ice. 3 oz Tanqueray gin, 1 oz 50% (100-proof) Stolichnaya vodka, 1/2 oz Lillet Blanc, 1/8 teaspoon (or less) quinine powder or, in desperation, 2 dashes of bitters. Strain into a chilled cocktail glass and twist a large swatch of thin-cut lemon peel over the top.”
 
The recipe concluded, “Shoot somebody evil.”