I know I'm late to jump on the trolley, but I played through Portal 2 and it's right up there in my top 5 favourite games.
An amazing trip, well crafted and satisfying.
LIGHT SPOILERS CONTAINED IN THE SONG'S LYRICS IN THE VIDEOS DOWN HERE.
ALSO IT'S THE END CREDITS, SO YES ... IT COMES AT THE END.
-->AND IF YOU HAVEN'T PLAYED THE GAME, DEFINITELY STAY AWAY FROM "TURRET SONG" VIDEOS THAT POP UP AS SUGGESTIONS. <---
I just can't stop listening to this song. SO GOOD!
I haven't played the 1st Portal, but it also has a great ending song.