There are literally thousands of amaros in Italy (as many as there are moonshiners, i reckon). Fernet is one of my faves, but mostly because it is widely available in the USA, and not too sweet (some of them, like Averna, have a molasses-like consistency, still good, but no more than one).

I guess Cynar would be my fave (it's a bottle with an artichoke on the label), as well as Amaro Montenegro, which I used to drink as a kid. For some reason.