Abbey Road, for both the "truthiness" of it being "last" w/r/t recording timeframe and with "The End" as the closing track. Also you can really hear the hate for each other if you listen closely. That said, Let It Be was worked on even after Abbey Road was released and was still released kinda-sorta unfinished.
I, too, think Abbey Road is the superior album. But I prefer, 1 v. 1, the songs on Let It Be over the individual songs on Abbey Road.