I am drawn to re-read certain books on a very regular basis.
I always read Hardy's Jude the Obscure once a year. It is such a depressing book; maybe it's that which makes me feel so much better once the final page is turned.
Stella Gibbons' Cold Comfort Farm is another that I re-read regularly (I've just finished it for the 100th time).
But perhaps the book I return to the most often is Evelyn Waugh's Decline and Fall. My ancient 1937 Penguin copy is falling apart from over usage; it requires some serious mending.
The book, which was dedicated to Harold Acton, contains this Author's Note (below), which, frankly, I would have thought somewhat superfluous.