Buncha tree huggin' hippies. Quit knockin' energy drinks because you have some sort of colon cleansing diet scheme. I'd rather sip some liquid energy than worry about eating the right combo of proteins and carbs. That's right bitches, I'm lazy.
Anyhow, here's what I can remember that I've tried.
Red Bull - Great
Red Bull Sugar Free - Great. Best Sugar Free one.
Red Jack
Ampd - Worthless unless you like concentrated Mountain Dew
NOS - Not bad. Odd after taste. Energy didn't last very long.
Starbuck's Double Shot
Monster
Monster Sugar Free
I know I've tried alot more (ask Racing Rice; he sees them), but I can't think of the names. The Red Bull's are my favorites by far. They don't taste like fizzy sugar water and they don't leave a bad taste in my mouth.