The only one I will occasionally buy is "5 hour energy". A little shot, no volume really, not carbonated. Lots of B vitamin in it. But that is only on that first day off from ththe FD, where we were running a solid 24 hours with little to no rest, or the days of driving almost clear across Texas. Haven't had one in this year. Best thing for me is an attempt at 8 hours of sleep, coffee, water, water, water the rest of the day. (Beer after 5 or 6).

I drink a Monster every morning and have done that for 10+ years straight. Less than 10 days in the last 10 years I've not had one.
I should quit that.