A few things to note first:

0. Fresh ground beans are always better than freeze dried or instant.

If you want caffeine, get a light roast. The darker the blend, the less caffeine.

Coffee black is bitter (I like it that way), so add sugar & creme to suit your taste.

Honey is also good in place of sugar.

A little spice can dramatically change it. A dash of cinnamon, for example. Or pumpkin spice in season.

That said, if I was your friend serving you coffee as a taste test, I would grind up fresh beans, BREW it, and let you try a small taste cup prepared different ways. The first being with a little sugar and a dash of cinnamon.