If you've got a nice collection of scotch, get a bottle of Drambuie (also technically scotch) to make the classic "Rusty Nail." You'll upset the scotch purists but delight your pallet
Recently I've been all about the "Boulevardier." It's an adaptation of a Negroni. My preferred blend: Campari, Carpano Antiqua sweet vermouth, Rebel Bourbon and a splash of club soda over ice. A couple cherries or an orange twist if I'm feeling fancy.