'Wound-up Penguin' specifically.
"Bring her back to him".
I must have seen this episode 50 times and EVERY SINGLE time it still gets me. I know the twist is coming but I am still crying like a baby by the end of the episode.
Such an amazing show. Really wish it had got more of a chance.
https://www.youtube.com/watch?v=ApZJRA3GKbM. This is the whole episode but the emotional knockout punch is the last 10 mins and starts at 35:00.