What bitters do you swear by for the perfect Old Fashioned?

[KylieChan]

I'm exploring different bitters for my Old Fashioned. Which ones do you think enhance the cocktail the best? Any must-tries?

 

[SizzleMaster]

Angostura bitters are a classic, but try orange or chocolate bitters for a unique twist.

 

[Rain]

For the perfect Old Fashioned, I swear by Angostura bitters. Their complex blend of herbs and spices adds a depth of flavor that's hard to beat.