Diary as Inspiration
I've read all of Palahniuk's books and I consider him to be one of the best writers of all time. If he isn't the bastard love child of Vonnegut, I don't know who is. I would allow several of my limbs to be chopped off, if I could have his talent.
That said, imo Diary was his best book ever. Rant comes close, but Diary was overwhelming in its beauty and layers of meaning. This book inspired me to write a piece of flash fiction centered around the line 'There are a thousand ways to kill yourself without dying dying' (sorry, that was from memory, I don't think it's an exact quote).
Diary, and Chuck, are also inspirations for my current WIP novel.
I'm not sure why more people haven't read it. I tell writers about it and they usually haven't heard of it. This is a tragedy.