January 31, 2013
The second season "Office" Valentine's episode is just pure "Office" goodness: Michael and Jan at corporate, the "Faces of Scranton" video, Phyllis' unending string of presents from Bob Vance, Vance Refrigeration, the first appearance of the Dwight bobblehead and poor Pam looking longingly after Jim when he wishes her a happy Valentine's Day.
Jump ahead to Season 7, with Michael and Holly getting their public displays of affection all over everyone, then declaring their love for each other. Oh, and Jim and Pam finally do it somewhere at work and we find out later that's when little Phillip was conceived. Awesome.