I think now I will have a lot of ideas, thanks in advance.
Scotch game

First of all you should take on d4. After white recaptures try this line...
Ok, thank you for your advice. I will try to apply this continuation. Black is ready to castle and is still attacking, it seems to be a promising game.

actually 4...nf6 is probably the most 'aggresive' line for black.
All right, I will try both, Bc5 and your advice, Nf6. Thanks for your commentary.

I prefer 4...Nf6, if only because I play that move against the Italian and Scotch Gambit, it helps transpositionally.

Taking the Knight 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Nxd4? is a known error for the reasons you stated. The most aggressive replies are 4...Bc5, 4...Qh4 and 4...Nf6, while I prefer 4...Bb4+ to stop White from developing naturally with 5.Nc3.
4...Qh4 is probably the most obviously aggressive move, but White gets an advantage with the most accurate play.
I like 4...Bb4+, interfering with White's development
After e4, e5, nf3, nc6, d4. What is the most aggressive reply playing as black? I am always tempted to play pawn takes d4 and if knight takes d4 I used to take the knight, and then the white queen takes knight. Black gives up the center and I do not feel so comfortable. I saw some chess opening theory, but I would like to share and discuss here. thanks.