Willa showing Isabel that Walter could belong in her "Washington life".
Walter's True Companions telling him to keep looking, despite the danger it may put them in.
The very fact that Walter was willing to give up the search in the first place despite thinking that to stop would risk his life or sanity.
Extrapoints for Walter, for not even contemplating the doubts Pope tried to seed into him about Leo.
Walter giving up a pair of valuable earrings to help Willa with her problem.
A minor one, but Willa finally manages to get into Walter's vault and finds the stash of awesome and potentially valuable stuff he has in there...and not only doesn't steal any of it, but lies about its contents when asked. (Given that favor in her clan seems to be pretty tightly tied to how much money you can bring in, she's passing up a pretty juicy opportunity out of respect for Walter.)
Walter determining that the missing girl was trying to drive the other girl who she shot to the hospital as opposed to the Everglades to dump her body, and being proved correct.
Especially heartwarming when you consider that he had nothing to go on but his gut instinct. It basically came down to a decision between believing that the girl was callous enough to let her victim die or believing that she was basically good and would do the right thing and he chose the latter. This episode shows us that, for all his paranoia and occasional Jerkass behavior, Walter really is one of the good guys.
When Willa finds out about the guy who killed Leo's family, her first instinct is to find him and beat the living hell out of him. Leo's not happy about her doing that, but the fact that she feels such burning anger on his behalf is quite touching.
When Uncle Shadrach tells Willa to "Go on back to The End Of The World and await her wedding day" she angrily responds "Ends of the Earth!" Normally, this is a Running Gag used to get laughs, but her passion and defiance here just serve to illustrate how much she's come to care about Walter and Leo. Doubles as a CMOA for Willa.