Lost S6E09 "Ab Aeterno"
This was one of the best episodes yet. Ever since his first appearance, Richard had left quite the impression on me, and I only grew to like him more as the series went on and his character developed. It was fantastic to finally get a glimpse at his backstory, see why he's on the Island and what his motivations are. I'm hoping this isn't the only episode focused on him, but considering how many are left, that's probably the case. Either way, this was wonderful.