gin
For starters, a true martini uses gin, not vodka.Beyond that, it is up to the bartender or whoever as to what kind of vodka you use for a vodka martini. That said, plain vodka appears to be most common.
I would recommend using this recipe to try making a vodka martini, http://www.foodnetwork.com/recipes/the-cookworks/the-classic-vodka-martini-recipe/index.html.
It is a gin or vodka martini made with no vermouth
He drinks a vodka martini "shaken, not stirred."
A vodka martini is often made with 2 parts vodka to 1 part vermouth so 1 1/2 oz vodka and 3/4 oz vermouth.
Vodka Martini (shaken, not stirred) and in recent films, the Vespa Martini
A vodka martini
Martini's
Vodka Martini (shaken, not stirred) and in recent films, the Vespa Martini
Black Star Liner
There are bartender receipe books that you can find on ebay or amazon or even barnes and nobles that would have many drink receipes including vodka martini.
Whiskey or whisky can have an ABV of at least 40%..... often times up to 46%. The alcohol by volume (ABV) of a martini can vary depending on the ingredients and how it's made, but it's usually around 28.7%–31%: Gin martini A gin martini typically has an ABV of around 30%, or 60 proof. The ice in the drink slightly reduces the ABV from the gin's bottling proof. Vodka martini The ABV of a vodka martini depends on the ratio of vodka to vermouth. A drier martini with more vodka will have a higher ABV than a wetter martini with more vermouth. Classic martini A classic martini has an ABV of around 28.7% when made with 27.25 ml of pure alcohol and 20 ml of water. Martinis are considered strong drinks and are usually served in short glasses, no more than 3–4 ounces.