I drank, Rockstar (the purple one) and Monster, Red Bull etc but it has no benefit whatsoever to my energy levels i just like the taste. I usrd to drink them but they just make ya fat so i had to give em up, it was either that or stop drinkin Bundy & Coke and Beer and i couldnt do that.
When im riding though its usually just water or weak cordial coz tap water tastes like poo!