These days, there seems to be a lack of great male supporting characters in anime. The average series tends to feature far more girls than guys, and the men are usually either the main character or the main character’s sidekick. The only shows that have a significant number of male characters and actors tend to be aimed at women, such as Hetalia or Kuroshitsuji (neither of which I watched, by the way). Still, there was at least one excellent anime of 2010 that brought forward a slew of great male supporting roles.
(There were originally more nominees for this category, but the only ones I ended up writing about were the ones from Durarara!!)