The two knight defense usually leads to a sharp game. Sacrifices are very common here for black as well as for white. This opening is played at the very top level even today.
Here are some variations of 2 Knights game
Max Lange Attack:
1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Nc3 Nxe4 5. Nxe4 d5 (Black sacrifices a knight for e pawn and later gains the material back by forking white’s knight and bishop).
1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. d4 exd4 5. e5 d5 6. Bb5 Ne4