Every time I read "To Kill a Mockingbird" I am boggled by how good the book is. Every aspect of it: character, voice, plot, timing. It's a masterpiece, and far and away my favorite book. It's simultaneously a inspiration to get back into writing and a discouragement when I see how far my writing skills have to go.
I read it every year or so. I started reading it again this evening, and I was only able to set it aside in the wee hours of the morning to go to bed because I had reached a mildly depressing point. I read it for the first time when I was in college, and I'm glad I didn't read it earlier because I don't think I would have appreciated it. As it is, I have no doubt that if and when I become a published author, Harper Lee will be a clear inspiration in my work.