Amy's the girl we want to succeed. Well, kind of. Mostly, we just want her to get a life already and get a little bit of perspective on the dysfunctional mess that is her father. But yeah, go, Amy, go! You are our sweet, if overly self-sacrificing, protagonist, and we are watching you grow up, mature, and get out in the world to make a life for yourself.
That goes double for Arthur. However lame of a life Amy has, at least she's not a sad sack at 40. If hers is a coming-of-age story, Arthur is on a finding-yourself arc. He is a gentle and kind man who has good moral instincts, despite a totally horrendous childhood. And want this nice guy to finish first.