Obi-Wan's speech in the original Star Wars (aka "The Time Where Building a Death Star Was a Pretty Reasonable Plan") has stuck in the craw of geeks for a long time - he speaks about Anakin and Darth Vader as if they were two completely separate people. And when it's revealed that Vader and Anakin are actually the same person, the speech felt like a very awkward way to put what happened and almost felt like Obi-Wan was just lying to Luke for no reason.
But add in some somber music and poignant flashbacks to the final moments between Anakin Skywalker and Obi-Wan Kenobi, and suddenly the scene makes perfect sense - and is the rare time that re-editing a Star Wars movie decades later ACTUALLY IMPROVES THINGS. It's pretty incredible - and strangely moving, in a way that almost makes the Prequels feel like they were worth it:
George Lucas maybe should have done something like this, instead of filling the backgrounds with CGI dewbacks and adding in a legitimately awful song.