Indexing by Seanan McGuire
One of the first things that I wrote that I actually remember what happened was a Finnish language assignment of my sister's (she wrote the one she actually turned in but I was so inspired by the assignment that I wrote one just for me); change a key aspect of some fairy-tale and write the story. I've been hooked on subversive fairy-tales ever since.
This book is something that combines both of those elements with dry, dark humor and an episodic story-telling style so reminiscent of all those cop shows I know and love. Every time I read this (I've lost count) I am both in awe of McGuire's work and kicking myself that she got there first.
Night Watch by Terry Pratchett
Sam Vimes in Night Watch is basically a noir hero who's trying to do good. He's Casablanca's Rick Blaine after Elsa gets on that plane (sorry for the spoilers but it's over 70 years old and spoiler warnings have an age limit). He is mainly interested in keeping the piece and protecting a few people.
What he gets is a whole mess of trouble. The Unmentionables, Ankh-Morpork's then patrician's private police, do not like the man who refuses to hand over curfew breakers to them for torturing. The book is filled with social commentary as well as ruminations on the nature of right and wrong.
Pratchett is one of the first authors I started reading who showed me just how subversive humor can be. Because it's "just humorous fantasy", Pratchett can do and say things that "serious" writers would have to work a lot harder for. Night Watch is very much "message fiction" but because it's also laugh-out-loud funny I've never heard it accused of being that. The book sticks with me and I keep coming back to it at least once every year.
Kuka lohduttaisi Nyytiä? By Tove Jansson
I loved this book as a teenager, heck I still love it, because it assured me that however I was feeling at the time, there were people out there who got me and would love me for me. I know it sounds trite but as a writer I would love to have that kind of impact on another person's life. It is, after all, a part of why I write.