The Fall of Centauri Prime: Londo comes to see G'Kar one last time before he gets the Keeper, as long as he's still alone in his mind, and they go from joking to...

G: Mollari... my people can never forgive your people. You understand that, do you not?
L: Yes.
G: But I can forgive you.

And just to make sure I really cry each time, they embrace before parting.