I was just wondering what are some the most tactical or aggressive chess openings for white or black.

KID, Sicilian, King's Gambit, Ruy Lopez, to name a few.

The Slav can be quite tactical oriented, as the last WCC demonstrated.  The French Winawer can also a tactical wonderland.

In general, gambits tend to be sharper than other openings: Scotch Gambit, King's Gambit, Evans Gambit, Vienna Gambit, Dutch Staunton Gambit, Budapest Gambit, Queen's Gambit Declined Albin Counter-gambit, Benko Gambit and QGD Semi-Slav Botvinnik.  Of the non-gambit lines, the Guioco Piano/Two Knight's complex and the King's Indian Defence are regarded as fairly sharp.

For me, it's the Ruy Lopez...I find it very tactical.  I have a pretty good rote memory and this is the opening I find has more tiny potential twists and ramifications than the others I've encountered.  Of course, I know nothing about d pawn openings.

king's gambit.  really.

WOOOOOT No one3 mentioned Blackmar-Diemer Gambit???????????Most aggressive of them all ;) It will give you such a thrill when playing it that people will think that you are high....it will give you reputation and respect....chess players will want to be like you and have your guts....Well you get the idea

oupps. that smile is overpixeled

Although some Caro variations are a little dull, the Nc3!? variation of the advance and the Milner-Barry gambit are some of the sharpest lines available.

The most tactical by far would have to be the Poison Pawn Najdorf. In no other opening have I seen computer traps that take nearly 40 moves to execute as has been demonstrated in the Najdorf PP.

As far as most aggressive, I tend to feel the h-file blitz against the Dutch defense is probably the most brutal cave-man style one can adopt. Roman has a video on it here on Chess.com that goes over a game where Nakamura used it to crush another master.

The Sveshnikov Sicilian is one of the hairiest/most tactical openings I have ever played. One mistake will often get you crushed, like in this game:

How about the Sicilian Dragon?

KGA is quite sharp, but my favorite is the KID. 

What a game, BigTy!

that smilie is going supernova!

botvinnik & najdorf

By far the Semi-Slav Botvinnik.

Yeah!

what about the fried liver attack?

a good one, but not to be used often, a surprise opening,  The Polish ( Sokolsky/Orang-utan ), if it's good for Fischer & co ( Tarktower, Sokolsky, Lapshun, ...etc ), t'is good for all, if you've got ze balls, yo!