i was quite impressed the first time i heard 'biko'.
Good call! Incredibly engaging, emotional climax to a mind-bending album from start to finish.
+1 on "Day In The Life" and "Golden Slumbers/Carry That Weight/The End" from Sgt Pepper's & Abbey Road respectively (I always considered "Her Majesty" more of a bonus track than the actual last cut on the album, fwiw.)
One that comes to mind is "Safe (Canon Song)" from Chris Squire's Fish Out Of Water album. After this long, involved, dense orchestral composition there's this brief, quiet little ambient coda performed on a heavily-reverberated bass, that just seems the perfect delicate capper for all the bombast that's come before.