Sopranos is an easy no. 1 for me. Breaking Bad was right up there too. In both cases I went back years later and rewatched the finales, then got sucked in and ended up watching the entire series again.

I also really liked the Battlestar Galactica (2004) final episode.

I was a huge Seinfeld fan but had stopped watching by the time the finale rolled around and didn't see it until years later. It's nowhere close to being one of the best episodes they made (it's not even the best episode of the pretty weak final season), but I'm not sure it was the catastrophe it was made out to be at the time.

Lost started extremely strong, first season is right up there with the best start to any show I've seen and the transition into the second season was masterful. But the wheels fell off for good a few seasons before the finale, so I didn't take it too hard when they weren't able to tie everything together at the end.

What's the extended version of the BSG Finale? Would that have been the one I saw on Netflix? Or did they repackage it as a separate thing?

Not a Ricky Hitler fan, eh?