What's a classy and clean-tasting highball or cocktail to order at a bar?

I just graduated and left my college town of Madison, WI, and I need some ideas. I really love gimlets, a good old-fashioned, and sidecars (but those are a bit too sweet for my tastes). I also love anything that merits a real glass even in the cheapest of college bars (where plastic is the default). Suggestions, and include some reasoning and general directions on how to make it. Thanks!