I think the scene with Arya killing that dude then Hound gatting some fools is my all time favorite in the history of film/television. That storyline will also probably be my favorite if it goes in the right direction. I'm not head over heels with Arya, but I am head over heels with Hound, and if Arya turns into a stone cold killer with his help, I'll wet my pants
If Arya and Hound part ways, I will lose some interest in Arya though. It's because Hound is kinda just the best