Coffee

Depends on the Scotch. I had a speakeasy tiki bar, i.e. unlicensced and strictly word-of-mouth, for a couple years. I used the whiskey sour as a specific example; I played around for a long time at making my ideal whiskey sour. Top shelf, wells, Islay, Speyside, Highland, playing around with sourcing the eggs for the whites vs. using dried albumin, Amarena vs (real) Maraschino... you get the idea. Lots of my supertaster (https://en.wikipedia.org/wiki/Supertaster) friends sampled more cocktails than might be healthy. :D The winning recipe used Clan Macgregor Scotch, which is absolutely a nasty well bottle. The kind of bottle I wouldn't serve to even people I hate. :D But the final result won blind taste tests and is much more than the sum of its parts.

I have some really rare and expensive rums. I would never subject something like, say, Plantation (now Planteray) Trinidad 2001 to a rum and coke. I think even a cocktail that showcases a spirit, such as the Mai Tai, covers up too much of the complexity of high-end spirits, becoming less than the sum of its parts. Some spirits are just meant to stand alone, maybe neatened. Bringing this back to coffee, most great beans IMO are similarly meant to stand alone.

Now, all that said, garbage in, garbage out. For most anything that goes into the pie hole, I agree that one should use the best one can find within certain contexts. Planteray OFTD or Stiggins in a double R&C, with a homemade cola, fresh-squeezed Meyer lemon, and .5mL of double-strength vanilla... <chef's kiss!>