Guilty pleasure books I have read more times than I can begin to count (and own in paperback & on my kindle...):
Sacred Sins by Nora Roberts & it's sequel (not as good, but nearly) Brazen Virtue by Nora Roberts. I don't what it is about these particular books of hers - I guess I love the idea of DC in the 80s?? They're murder mysteries but with her usual romance. They both had me guessing until the very end too, unlike some of her others where it was obvious whodunit.
The Da Vinci Code by Dan Brown
The entire Harry Potter series, but especially books 1-3 - sadly not available in kindle form
Others I love that are less "guilty pleasure", have read at least twice:
Rebecca by Daphne Du Maurier
Jamaica Inn by Daphne Du Maurier
The Tenderness of Wolves by Stef Penney
I'm currently reading Shake Hands with the Devil: The Failure of Humanity in Rwanda by Romeo Dallaire, about the 1994 genocide in Rwanda. It's absolutely heart wrenching but is on my list of favourite books because I wish everyone would read it. I also appreciate reading about it from a "real life" military perspective rather than the often watered down political version we get in the news/from other sources. Maybe if we all pay attention and don't ignore what we don't want to deal with/would rather pretend isn't happening, the next genocide attempt will be stopped before it gets started.
"Choose to chance the rapids, and dare to dance the tides" - Garth Brooks
"With your permission, dear, I'll take my fences one at a time" - Maggie Smith, Downton Abbey