I don't rate individual TV episodes, because I like to keep my ratings to just movies and entire shows so my list of ratings don't get too cluttered or out of control. Rest assured, however- this is a 10/10 episode.
The Good Place proved to be a very interesting journey. For me at least, perhaps it wasn't the most consistent show, but when it was great, it was seriously great. The first season was pretty good up until that fantastic twist in the season finale, which set up a great season 2, which then segued to a less stunning but still quite satisfying season 3. Season 4 I had mixed feelings on, but I had faith in Michael Schur and the rest of the cast and crew, and thankfully my faith was rewarded with this excellent finale.
It's rare for a show to have one of its best episodes be the finale (there's a certain show about dragons and stuff that finished last year, which comes to mind as one that ended as a disappointment to most). But perhaps other than the season 1 finale, this might be the finest single episode of The Good Place.
So why am I rambling on without saying anything specific about what made it great? It's because I'm afraid of ruining anything. I went in with moderately high expectations and no knowledge of what would happen, and I was moved, surprised, and entertained beyond what I imagined I would be. This is coming from someone who likes the show a lot, but hasn't unequivocally loved every single episode.
This finale did not disappoint. Fear not, anyone who thought The Good Place wouldn't stick the landing, especially if you were like me and found season 4 overall slightly weaker than what came before. This ending made it all worth it. Shows as interesting and quirky and likeable as The Good Place don't come around too often, and now that it's all over, I'm thankful for the time I spent watching it.