Malcolm Reynolds. Probably gonna get flamed for this, but he was a jerk with a heart of gold, except they forgot to write in the heart of gold part. I forgive the TV series because A. he actually had some decent moments (could've used a few more) but B. the series was canceled prematurely, so I always thought he had more character development just beyond the horizon.
Then I watched Serenity, and I learned that it was a-ok to hate that prick. That selfish, inconsiderate, short tempered, reckless, intolerable, stuck up, controlling, "witty" PRICK!