The issue I see with this debate is that there's far too much assumption involved. When I think of someone being a dirty fighter, I think of something intentional. Without being the actual person comitting the act, you never really know if they did something intentionally, or if it was an honest mistake. Therefore making statements like, "Intentional eye poking" is really just a guess. I think fighters who choose to do things like foot stomping, mouth/nose covering, or fighters with blatant disregard to their opponent's body/health.
Are some people who come to mind immediately.