I don't regularly take pre workout drinks, just coffee. But occasionally I'll plunk down 3 bucks for a Speed Stack. It's supposedly got all kinds of stuff in it like synephrine, bitter orange, vinpocetine and DMAE in it. I'm not sure what all that stuff really does, but it certainly kicks me up for a workout if I am dragging.
I worry that there's some form of illegal stimulant in there.