A girl needs diversity....
What a girl needs at this point is a pretty good question. Arya just got complicated. The revenge monkey was marching into the Red Keep to kill Cersei; Sandor broke through at the last moment, made her realize that Cersei was doomed whether Arya killed her or not, and basically told Arya to choose life. Then she stumbled around the wreck of King's Landing long enough to break out of her silo, recognize that the suffering of so many innocents was fully the equal of her own, and discover compassion. Arya, compassion. Does not compute. A new character has been born.
She may end up with Gendry after all.