The Danish Gambit is an ultra-agressive opening for white. It is not commonly seen in tournament play since lines have been found to blunt it. It is still occasionally seen in amateur play though. In this gambit white sacks 3 pawns for one, hoping to deliver a qiuck knockout with his activated pieces. Black tries to blunt white's ferocious assault, sometimes giving white a pawn or two back. Black's goal is to try to survive and trade off everything and go into an endgame with an advantage in material. Here is the gambit:
Of course you don't always have to take all those pawns! Here is another option
Or there are very very crazy games. There are many variations.