This is a great thread! I was surprised to find that some don't love this fine elixir. The Bronco prefers his Branca in large sips from a cordial glass following a good meal. However, this cocktail, the Industry Sour, from the fine bartenders at Taste in St. Louis is also great:
1 oz Fernet-Branca
1 oz green chartreuse
1 oz lime juice
1 oz simple syrup
This is the recipe they use. It's quite complex, interesting, and at moments challenging. As it is, it's a touch sweet for me. But cutting the sugar in half throws things too out of whack. Meddlers beware.