I usually prefer anything natural - brunette, blonde, etc. Not a huge fan of colored or bleached hair. If I had to choose, I'd probably also be on team brunette or black.
Doesn't really matter much to me, but I do agree that the general rarity red hair catches the eye. I'm not really a huge fan of unnatural dyed hair colors, but it's never been a deal breaker.
In game I love bleached and purple hair, the other unusual colors like pink, blue and green too. IRL I keep the basic because I like to preserve the little left of my sanity intact