It's hard to find an energy drink which is, at the same time, tasty and buzz inducing.  Rockstar has done a great job with Rockstar Punched, a fruit punch flavored energy drink which contains a decent amount of buzz along with a flavor which won't put you off your lunch.

At 260 calories per 16oz can, it falls right into the "guilty pleasure" department of Energy Drinks when on a diet, but you can do much, much worse in the energy drink market than Rockstar Punched.

The fruit punch flavor of Punched is similar to Hawaiian Punch.  In fact, except for the fact that the container says it's an energy drink, you wouldn't notice drinking it until the buzz hits you;  it has no bitter taste like other energy drinks, and it's not cloyingly sweet like some drinks which try to hide the bitterness of the energy components might be.  My guess is that the tart flavors of citric acid do a good job of "hiding" the bitter flavor of the energy chemicals.

The buzz is pleasant and not overdone;  this won't give you the jitters, it'll just give you enough of a kick in the pants to push you over the noonday hump... or through the 15th hour of a overnight session of Sam and Max.

I highly recommend Rockstar Punched to anyone who likes artificially flavored fruit punch who wants a buzz and who can afford the 260 calorie hit in their diet.