My favorite look for Rogue has always been the costume she wore when I first discovered the character in Uncanny X-Men #171, the issue where she shows up on the X-Men’s doorstep and ends up joining the team. Here she is just prior to that appearance when she was still a member of the Brotherhood of Evil Mutants and a bad guy.
I also prefer short hair on Rogue. I don’t know if it was ever established in comic book lore one way or another, but I always liked to think that even contact with her hair could cause an uncontrollable transfer of powers and memories so just out of concern for her own teammates, she would keep her own hair short.