The perfect Manhattan cocktail starts with a good rye whiskey like Jefferson's Straight Rye Whiskey. This rye is well rounded with spice and mint notes. The very next thing needed for a perfect Manhattan, and the most important in my opinion, is sweet vermouth. Using a good quality sweet vermouth is the difference between a great cocktail and a bad one.
I have two favorite types of sweet vermouth I like to use. The first is Antica Sweet Vermouth. This stuff is classic and amazing. It's sweet without being over powering with just a slight hint of herbal notes. This is my stand-by vermouth.
If I'm feeling adventurous I'll go with Punt e Mes Vermouth. This vermouth has a much more complex and herbal quality.
So here is the perfect recipe for a perfect Manhattan!
2 oz Rye Whiskey
1 oz Sweet Vermouth
1 dash Angoustura Bitters
1/2 dash Orange Bitters