When the Hound Saves Arya and Conquers His Fears
The Hound tackles two of his biggest fears, fire and his older brother, in the penultimate episode of season eight. He kills the zombiefied Mountain by tackling him into the burning rubble that King's Landing is rapidly becoming, the both of them likely dying on impact. But that's only after he manages to convince Arya to let go of her revenge mission to kill Cersei and save herself. A true friend till the end.