Amaros are Italian digestifs that are an herbal combination of bitter and sweet. They are made by adding herbs and sugar to grappa, a rather nasty spirit distilled from the dregs of Italian wine-making. I first encountered them at The Stained Glass in Evanston, and have since had them in a few other restaurants, including a flight at Marea in New York. They are flavored with different herbs, including cardamom and rhubarb. Each producer has their own unique recipe.
In the picture above, they are arranged , more or less, from bitterest to sweetest, with the one on the right more like a liqueur. My favorite is still the first one I ever tasted, Amaro Nonino.
The one on the extreme left is too bitter for me to drink, but the rest are all interesting and good. Since they are simultaneously bitter and sweet, most work either before or after a meal.