I tried the new Mountain Dew AMP today; pretty good stuff... I've now tried like every single energy drink available at gas stations. Here are the rankings, based on my personal taste tests (results are subject to change):

1. Mountain Dew AMP
2. EAS piranha - fruit punch flavored
3. (tie) 180; Hansen's
3. (3-way tie) Red Bull; Sobe Adrenaline Rush; BOMBA - yellow
4. (tie) KMX; Extreme Energy Drink
5. BOMBA - blue