Its not that Vodka Martinis, Sweet Martinis or any other Martinis are wrong but if someone says just "Martini" then they mean Dry Vermouth and Gin
And if a barman says "Gin or Vodka?" find another bar to drink in. They are allowed to ask 3 questions: "Which Gin?", "Which Vermouth?" and "Olive or twist?"
The ratio of the two things is up to you. "Dry" is much more gin than vermouth and "Wet" can have equal amounts of both. Some people think you should flavour the glass with vermouth but not leave any in it and just add Gin. I used to think that but I don't any more: Vermouth is an aromatic drink based on wine and Gin is all about the "aromats" so the right mix complements each other
This is what I like
Directions
Put your Martini Glass in the freezer for an hour
Pour 1 part cold (from the fridge) Vermouth in the glass and add 5 parts Gin from a cocktail shaker with ice.
I personally like olives but a "twist" is nice too. To make a twist peel a strip of rind off a lemon and twist it hard over the glass to forces some lemon oil out and then drop it in
