I just finished Cosmos.
I actually felt tears swell up as Sagan delivered the final lines of the update segment on the episode "Who Speaks For Earth"
This one makes the list and then some. I have never seen a science program based on fact and speculation that generates such an emotional response. It doesn't just bluntly state the facts, but speculates on many great possibilites, such as the very internet I am using to say this message.
While I admit I wasn't too interested at first, Sagan has grabbed me and fascinated me in ways that I cannot describe. It was as if 2001: A Space Odyssey suddenly became real, and now it shall never be fiction for me again. Out there is a place that was once an alien thing marred by my superstitions, but now it is more real than it ever has been.
Sagan was one of the world's finest dreamers, and with many of his ideas now realities, one has to wonder what new discoveries he fortold shall follow.
Cosmos is more than science, more than art, it a collection of possiblities that all of humanity can make real if we apply ourselves. I plan to start right now.