The Stinger packs a punch. It's a classic cocktail that is the combination of Cognac and white crème de menthe.
Good crème de menthe is essential in a Stinger. If you use one that's low quality, it will definitely show through. I'm a big fan of Tempus Fugit's Crème de Menthe Glaciale and highly encourage you to use it if you can find it. Feel free to use whatever good brandy you have on hand. There are a lot of options out there including domestic products, Cognac, and Armagnac among others and will lend their individual characteristics to the drink. I choose to serve my Stinger up, and it's a dangerously drinkable cocktail. It has a pretty hefty amount of booze, but it goes down so easy.
Some people like to serve it on crushed ice, but I think it runs the risk of diluting the cocktail too much. I encourage you to make it with crushed ice if you're at all curious. It's somewhat reminiscent of a julep in that form, but easier to make when mint is out of season (or just not in your fridge).