Fantastic Cast.
Fantastic soundtrack.
Brilliant editing which gives each episode even more energy.
The show is well-produced, the cast all play their roles to perfection. Episodes can be rewatched a dozen times and still be enjoyable, nay, MORE enjoyable each time.
Extra fun happens when an episode is based (loosely) on a movie, such as the Dead Poet Society send-up. LOL @ Claire: "your MOM is irrelevant". The season-enders are sure to bring a tear to one's eye as well.