LOST: this episode was more of a prologue to the season finale, and no island mysteries were unlocked, but, for me, this is a good example of why the show is great. I do not even like Charlie that much but I got genuinely choked up watching this episode. Mysteries aside, Lost tells good stories, which creates a phenomenal amount of sympathy for its main characters. Desmond's premonitions allow a story like this; right there is an often forgotten about virtue of science fiction -- as in Solaris, sci-fi is better with this human scope. And heading into finale territory I expected to be bored by the obligatory flashback, a flashback not revealing secrets; but the "Greatest Hits" thing -- using flashbacks for single memories rather than for telling a story -- really made the device feel fresh (not an easy thing to do three seasons in).
No one every talks about other shows in the comments, but you are welcome to.