Books where being kind is the “correct” choice

I'm looking for stories where kindness is rewarded. The real world sucks enough already, let me read something that makes me want to believe in the power of supporting and trying to understand each other.

The problem is, it seems that these themes often lead to either mindless fluff or children's books. I'm not currently interested in either. I read a lot of speculative fiction, but would actually be interested in literary fiction with kindness as a core theme. It seems that often the more highly a book is regarded, the cynical the world-view in it is.

One of my favourite authors for this kind of feeling is Becky Chambers, but I've already read everything by her. Terry Pratchett's also good, as is Catherynne Valente.