The Thorn Birds
I reread this almost every year at this time because it gives me pure joy. I never read it as a kid, but I remember the steamy miniseries. I finally picked it up five years ago and had such a thoroughly fantastic time. I like a big epic sprawl of a book in summertime. I love that it covers more than half a century in the family's life. It's soapy and heartfelt—of its own time and place. I always enjoy dipping back into it.