Firefly? No disrespect, but not even in the top 100 as far as I'm concerned. And even number 2, whatever it is, doesn't come close to Game of Thrones in my books. The series is mind-bogingly epic. I can't think of anything else that's ever been done for TV that approaches its scale/breadth.

GoT is spectacular not only for its source material which brings the overall plot and most of the characters, but its production is phenomenal. Sets, locations, costumes, scripts, dialog. And there's occasional boobies.

I'm saving reading the books until at least a few more seasons of the show have gone by. No matter how good a filmed "version" is, nothing can really ever live up to the original literary work.

Seeing it on the small screen however, has made me really want to see another epic series of stories produced. Thieve's World. Now that could be great, but it would be an insane challenge to do well.