My thoughts
Well, I only like /f, simply because I enjoy tickling females.
My favourite is m/f, simply because it's the easiest role to place myself in, as a male ler tickling a female lee. f/f is a close second, simply because it's still a female being tickled, and there's another female to add to the fantasy.
f/m I dislike, because I don't enjoy being tickled and don't want to place myself into that role, and m/m I dislike because I have no interest in tickling males, or being tickled by another.