Master Plan (Season 2, Episode 23)

Even before “Leslie’s House,” it was clear that Parks and Recreation was shaping up into something special. But the prospect of adding two new faces - even if those faces are as adorable as Adam Scott’s and Rob Lowe’s - to the cast could have risked overstuffing a show already dangerously full of characters fighting for airtime. Ironically, a half-hour featuring Leslie poorly (and Ron giddily) reacting to news of impending budget cuts was Parks and Recreation at its most crowded. The introduction of Ben and Chris in “Master Plan” was also the show introducing its first major, non-Pit story arc, with Pawnee’s bankruptcy eventually culminating in “Harvest Festival” well into the following season. The show had mostly been a series of one-off episodes up until that point, largely maintaining continuity through callbacks and relationships (Andy and April’s own becoming a real possibility here, as the episode celebrates her 21st birthday). From “Master Plan” on, though, there was rarely ever a stretch of time where Leslie wasn’t working towards some greater goal, which helped open up the show to bigger and better venues from which to watch the Parks crew change.