I go for the clean shaven, military flat top myself. That’s what my father had from age 17, regulation US Navy, circa 1950. But really, men need to be neat and clean, well-groomed, have hair that cannot be mistaken for a woman.
A hair transplant out of vanity on a man is to me like a woman who gets a crew cut out of vanity. (Forget the exceptions, people with medical conditions, having chemo, corrective hair implanted to cover an injury, etc.)