Here is where, in my opinion, the biggest difference between a good and a great Manhattan is made. I try to stay away from the bottom shelf vermouth such as Martini. I’d rather spend my money on a good vermouth over a top shelf gin any day. My favorites are Punt e Mes, Cocchi Torino, and especially Carpano Antica. There are also dozens of really amazing Italian vermouths that you can experiment with, but Cocchi is a good place to start.
Bitters
Angostura bitters is where you want to be here. You can experiment with other bitters over time, but Angostura is the classic for a reason. While you can get Angostura bitters on Amazon, you can often also find them right next to the soda at any grocery store.
Cherries
I could write a whole post on maraschino cherries. I feel they make all the difference in a good drink. Like with pasta or vermouth, Italian is the way to go here. Avoid the cheap supermarket candied cherries or “maraschino” cherries, and get the good stuff: Luxardo is the classic, amerena Toschi for an upscale pick (what I’m currently using), or Starlino as a young and hot newcomer. Not only is the quality of the cherry better, I use the liquor to add a little bit of sweetness to my Manhattan, which is not something you want to do with supermarket cherries. Don’t skimp on them, add 3-6 per drink, your tastebuds will thank you for it.