What are examples of very aggressive openings? One of my favorite openings is the King's Gambit.  It is extremely aggressive, and makes for a sharp tactical game without sacrificing too much material.  It isn't played much at the highest level at standard time controls, but even today it is occasionally used in blitz by top level players such as Hikaru Nakamura.
What other openings for black or white would force these kind of very aggressive, tactical, sharp and open games?  (Without putting yourself in too bad a position.)
The most (overly-)aggressive openings I know of that aren't too bad would probably be the Danish Gambit (Accepted) and the Fried Liver Attack.

Danish Gambit Accepted:
[FEN &quot;&quot;]
1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2 

White gets three open files and both bishops on open diagonals facing black's king; black gets two pawns.  Usually considered slightly better for black, but played occasionally even up to master level.

Fried Liver Attack:
[FEN &quot;&quot;]
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nxd5 6. Nxf7!? Kxf7 7. Qf3+ Ke6 8. Nc3  

White sacrifices a knight to get Black's king out right away.  Proper defense is extremely difficult over the board, but played correctly, black is thought to have a slight advantage.  In most lines, white wins their material back.