Lord of the Rings - well over 100 times. Love that book. Plus the other Tolkein ones, but we're only looking at up to 20 times with most of those.
Hitchhiker's Guide (etc), The Eyre Affair (etc), The Ship Who Sang (etc), Anne of Green Gables, Pride & Prejudice & Zombies (for a re-take on the classic), the Discworld books (read at least once every other year), Poirot... There are many, many books I have read many, many times.

All book club books are read twice: once quickly so I know the plot, the second slowly so I can discuss the book in-depth and talk about motivations etc. Plus so I can do a synopsis for the other book club members, who often don't even manage the once.