You know, those books that you have been reading for years, have old dog-eared copies of and will pick up when there is nothing new that takes your fancy.
Mine are:
Almost anything by F. Scott Fitzgerald, but especially The Beautiful and Damned.
Betty MacDonald - The Egg and I etc
Nancy Mitford Pursuit of Love, Love in a Cold Climate etc
J. D. Salinger Catcher in the Rye
Cold Comfort Farm