Depends on the guy, age, how it's done, cleanliness, etc.
Well I prefer it clean. Well when I envision it on my perfect guy its a 6'2, 200lb beach boy type of guy. Twenties, worn out, has a wave to it. Think Fabio without so much length and not exuding so much sexual passion. Lol But what I like may differ. For some long hair on a guy is four inches and up.
I think Fabio is creepy looking! It depend on the guy, some guys can pull it off and some guys look really dumb with long hair.
I grew up in the 60's - so long hair was the norm. Still on most men it doesn't look good. Younger men - depending on how they "do" it, can often get away with it, without it making them look awful.
My idea of a good looking man with longer hair - is Alex O'Loughlin during his Moonlight days. (TV show). Not overly long hair. Sexiest man alive in my opinion! (or not alive - tee hee....)
Now you all know my secret celeb crush....
Depends on the guy, the haircut, the cleanliness. Longish layered hair (like Simon Baker on "The Mentalist") can look good. Hair pulled back into a pony tail when a guy is bald on top - no, just no. Looks ridiculous.
Time and a place for everything. Longer hair generally looks better on younger men who still have nice thick hair. As it thins out, it's not that great long any more.
That goes for women, too, more often than not.
I knew a Native American man in Cal. and he had long black beautiful hair and what a body!! He was a hunk!! He had no hair on his body. I dated a guy that was Black and Native American and he said was not able to grown a full beard because he was part Native American .It depend on the men, even in Native American men, on how well they keep their hair clean, trim and have the right style that is good for them. My husband who is Ojibwe used to have long hair and he found that he can not managed his hair when he was working in the bush cutting trees. So he decided to have his hair cut so he could have clean hair after his shower from his work. He continued to have short hair and still have it today. Short hair for my husband is pretty good for me. I don't mind having men long hair, but I don't want men to have long beards or mustaches. My husband have mustache always trim so that I can lipread him.
Anyway, I tried to have my son when he was little to have long hair for Native tradition, but funny thing is that his hair is curly. I was shocked and I did not like the curly hairs. So I had him go to the barber and have his hair cut short. He continue to have short hair. So it depend on how they look and what type of style.
I do have curly hair now but back then I did not have curly hair.