What are the opposites of "detractor", "skeptic", or "pessimist" types?
Supporters, "experientialists" (not a label I really use since I've only ever labeled these people with a concept, but it does the job for now), and optimists (who quite often make great leaders).
Supports support and nurture you. Accurate, effective, intelligent, aware supporters who actually know how to get results you're interested in can be extremely effective. You'll find it hard to find these people, usually, but some can be found and some will support and give advice for free (such as if you are within an organisation--such as Toastmasters--with them or working with them on a project).
Experientialists know that life is more of an experience rather than something to "prove" and relate to it without fear as much as possible. These people usually live pretty consciously, and if not, at least they seem pretty alive and in alignment with themselves and their desires.
Optimists are people who see the present and can't help but imagine a better future. I'm an optimist and my "see a better future" vision is always on. In fact, some people see me as critical when, really, I'm just extremely optimistic and focus on how something can be improved (which comes from my Maximiser talent theme that I discovered by taking StrengthsFinder 2.0, which is a test you get from the book that is surprisingly called,
StrengthsFinder 2.0 
).
I'm an experientialist and an optimist. I'm not naturally a supporter, but I'm not bad at it when I do it since I've been modeling someone who is naturally a supporter/nurturer type.