NBC has kind of been a TV Graveyard for a few years now, hasn't it? While there have been some bright spots, like the non-cancellations of low-rated gems like Friday Night Lights and now Chuck, the network still can't launch a ratings hit. Even "hit" comedies The Office and 30 Rock receive pretty paltry viewership. Thus, each year now, NBC launches a bunch of new shows...and most of them don't survive. They also slowly give up on longer running series that still haven't broken out, like My Name Is Earl (4 seasons) and fan-favorite Life (2 seasons).
Fans of ER also know that the long-running program finally finished up its run back in April.
Which show in NBC's graveyard saddens you most? I've already come to peace with Lipstick Jungle, lost touch with Earl a few seasons ago (though still...not cool, NBC), and never got into Life, so personally I am most disappointed about the demise of the criminally underrated and highly inventive Kings.