Since I have a large patch of high-quality heirloom mint, my go-to drink for impressing guests is the Mint Julep.
Our generations-old family recipe uses "mint water" (a large amount of mint crushed in a small amount of water then strained), simple syrup (2:1 sugar to water, heated to dissolve then cooled) and bourbon in equal parts over ice.
Second is the margarita, on the rocks (no salt!). The way I learned it when I waited tables was tequila, triple sec, and Roses Lime in equal parts.
These are strong drinks but if you sip slowly the ice dilutes them at a steady rate without changing the inherent flavor profile very much.
I usually choose strong drinks and consume them very slowly, usually only 1 (occasionally 2).