Ginger ale beats everything. My favorite drink, period.
Actual (hot) ginger ale beats regular ginger ale, as long as it doesn't turn my throat on fire.
Otherwise, sprite beats mountain dew, pepsi and coke are about equal, dasani beats aquafina, barq's beats mug, and gatorade beats powerade.
I generally stay away from caffeine (don't ask me why, I just don't like my body depending on stimulants, yet I'M THE ONE not tired in the morning with all my friends at school. I guess that's probably because I get a decent amount of sleep, though.).