d5 is the best move, blocking the bishop
Openings against the fried liver?

You're welcome.
You can play Nf6 first as well, but it is a bit more complicated. After Ng5 by your opponent and after you play d5, and he takes the pawn with his own pawn, you would need to play Na5 and have some initiative in a pawn down position.
The solution I presented is more straightforward.

First, you have to notice that Fried Liver can not start unless you allow it so, and the dreaded Ng5 headache you are looking of panacea here is the knight attack.
Like it has been pointed out above, main line italian never allows the Knight Attack to happen in the first place.

Against the Fried Liver Attack for lower rating levels, for example around 700 where I'm at, the Black Night Gambit that GothamChess on YouTube did a video about has been very successful for me. I believe it's also called the Ponziani Steinitch Gambit or something similar.

People just insist calling this 4. Ng5 line the "Fried liver attack", even though it is not. The Fried liver is a piece sacrifice line that almost never happens.

Look up the Fritz variation. A lot of tactical lines to explore and so many people, even in the 1700+ range seem to not know how to play against it as white. There's also some really nice traps involved that I find people fall for at a surprisingly high rate under 1500.
People just insist calling this 4. Ng5 line the "Fried liver attack", even though it is not. The Fried liver is a piece sacrifice line that almost never happens.
You are correct that 4. Ng5 is not the Fried Liver, at least not always, it is still just one of the 2 Knights Defense mainlines at that point.
It’s Fried Liver only after 4… d5 5. exd5 Nxd5 6. Nxf7 and so on.
You are totally wrong about it almost never happening though. At higher levels that would probably be true, but at least sub 1500 rapid, it happens rather often. Sub 1000, I think even more likely, and most players on this site are sub 1000.

People just insist calling this 4. Ng5 line the "Fried liver attack", even though it is not. The Fried liver is a piece sacrifice line that almost never happens.
You are correct that 4. Ng5 is not the Fried Liver, at least not always, it is still just one of the 2 Knights Defense mainlines at that point.
It’s Fried Liver only after 4… d5 5. exd5 Nxd5 6. Nxf7 and so on.
You are totally wrong about it almost never happening though. At higher levels that would probably be true, but at least sub 1500 rapid, it happens rather often. Sub 1000, I think even more likely, and most players on this site are sub 1000.
There has to be a perfect storm where black knows nothing and goes into the Nxd5 line (that is likely, I admit) while white knows the sacrifice and plays it (very unlikely). Yeah, it may happen very occasionally, but certainly not "often".
People just insist calling this 4. Ng5 line the "Fried liver attack", even though it is not. The Fried liver is a piece sacrifice line that almost never happens.
You are correct that 4. Ng5 is not the Fried Liver, at least not always, it is still just one of the 2 Knights Defense mainlines at that point.
It’s Fried Liver only after 4… d5 5. exd5 Nxd5 6. Nxf7 and so on.
You are totally wrong about it almost never happening though. At higher levels that would probably be true, but at least sub 1500 rapid, it happens rather often. Sub 1000, I think even more likely, and most players on this site are sub 1000.
There has to be a perfect storm where black knows nothing and goes into the Nxd5 line (that is likely, I admit) while white knows the sacrifice and plays it (very unlikely). Yeah, it may happen very occasionally, but certainly not "often".
I play that line. And know the sac. My repertoire as white is based around the Italian game…
I have had dozens of games during the last couple months with Fried Liver. I think there were a couple 100% accurate games also (easy to avchieve with 7 book moves and a couple moves to mate after that).
You would be surprised how common this is. Way more common than the Two Kinghts defense mainline, believe me.
Me alone getting to play this dozens of times means, how commonly this happens is closer to often than never, I’d say.

Don't play the 2knights defence to avoid fried liver attack. Play 3...Bc5 instead aiming for 4...0-0 on the next move.

#14, if you take ALL the games played then fried liver is pretty rare
because you know it as white, you get it often
but as a black player, facing it is kinda rare
if you want to delve into stuff go to the other website and their "players database"
#16... you do realise we arent playing chatgpt chess right

My bad and thanks for pointing that out. Anyway, I don't recommend 2 knights defense to beginners exactly because of the 4.Ng5 move. Otherwise I have to show a bunch of theory that they'll never get to memorize. I keep it simple.
#14, if you take ALL the games played then fried liver is pretty rare
because you know it as white, you get it often
but as a black player, facing it is kinda rare
if you want to delve into stuff go to the other website and their "players database"
#16... you do realise we arent playing chatgpt chess right
If I get to play it a dozen times in a relatively short period of time, then it surely happens relatively often.
Of course it is not like most games played are the Fried Liver, but you do understand that ”almost never” would mean I would almost never get to play it.
Just yesterday, went to a library, played 5 games OTB, one of them I got to play, and win, with the Fried Liver attack.
What openings do you recommend against the fried liver? I'm getting wrecked by it every time.