Well I've mentioned this many times in class by my favorite books, a series by Joan D. Vinge which consists of The Snow Queen, World'd End, and The Summer Queen, are my go-to novels for comfort reading. They're familiar and rereading them is always a pleasure. I'm always caught up in the story no matter how many times I've read it and that's exactly why I read it.
I discovered the first of these books in my early days as a library volunteer. I picked it because I liked the cover and it was the biggest book I saw. I read then and have been hooked ever since! Nothing like a good ol' comfort read.