It's so wierd. I remember having a great time watching it, but right now I can't seem to remember what happens there...
Anyway, for best episode, I think I'll go with either Six Feet Under finale, or The shield finale. Both perfect in so many different ways.
I've recently watched The Sopranos for the first time ever. While I enjoyed it, I don't find it to be "the best show ever". Maybe your prespective changes over time. What I mean in, when it was aired, it was something else in TV, while today it's a great show, but nothing that hasn't been done.