Scandinavian!
What is the BEST OPENING AS BLACK AGAINST 1.E4?

If your willing to book up either a Sicilian you like or an aggressive set of 1.e5 openings would seem to suit your style. If you're wanting something more offbeat maybe Pirc, modern, or Alekhine.

There is no best opening against 1.e4.
Since you already play the Caro kann, you could give the Scandinavian a try. You will have the same pawn structures in general, a semi open board, and the Bishops do a lot of work till they are traded off.

c5 is usually an important move as black against 1 d4 and 1 e4 openings so you may as well get it out of the way with the sicilian. Playing the sicilian requires extensive preparation however. The best response to 1 e4 really is the one that results in positions that you like to play, so experiment. I play e4 and d4 as white, and play c6 (caro) vs 1 e4. After a few years of playing the caro I'd say i have most of the lines down well. It can be boring for sure but that's kind of the point, have no weaknesses and a good pawn structure and bore your opponent into making a mistake or trade down to a winning endgame. There are alot of aggressive responses from white to deal with in the caro however.
You should try the King's Indian Setup. It goes like this:
That's not the King's Indian. That is the Pirc. Two TOTALLY DIFFERENT openings!
The King's Indian Setup is not an official name. I know it the Pirc Defence.

Hi guys, I generally play the Caro Kann but I'm of kind of getting bored of it. Are there any other openings as black against 1. E4 you guys recommend? My style: Attacking, Tactical, Positional (Good at Open Positions: Using Sniper Bishops)
French Defense or King's Pawn

Since you like open boards and do well with line-pieces sweeping across the board, answer 1.e4 with 1...e5, accept all gambits, and dare white to do their worst. You will have to learn a lot more theory because white's options for openings are many, but your games will not have any of the issues of the Caro-Kann. If you enjoy utter chaos and not knowing if you are actually winning or losing your game, you can also play the Latvian Gambit.
personally I would do the sicillian