Not much of a coffee drinker as I prefer unsweetened tea. Or steamed tea. If I do drink coffee: black just like my heart. So long as filters are cleaned as appropriate.
I'm getting to a point where sweetener really bothers me in some drinks and foods.
Energy drinks are too addictive, but I did try some "Speed" energy drink awhile ago. Just a sip and the surge caused everything to become more colorful and vibrant for a moment as my senses and entire awareness suddenly perked up. Tingling in the base of the skull.
I'd recommend it to anyone driving late at night and starting to get sleepy at the wheel. A sip at a time 'll do ya fine. Just make sure you have food to burn during the intake or have eaten well prior or you'll have an intestinal demon you don't want (just like any other product in this category). Also make sure you have plenty of time to sleep for the crash once you come down off of it. It isn't going to be pretty.