Depends what you mean by "rereading". There are some books I'll occasionally dip into when I'm bored/apathetic/generally wanting something to read; the latest being Richard Molesworth's excellent Wiped, about the history of Doctor Who in the BBC archives (I recommend it), and Jon Preddle's two volume Timelink analysis of Doctor Who continuity, which I have to be honest I mainly disagree with (for example, his logic in placing Kinda in the early 1980s makes little sense given that Sanders' expedition is either a.) clearly a future expedition from Earth or b.) is an alien expedition that displays an unlikely knowledge of Earth hymnody ["Change and decay in all around I see, eh?"]. Take your pick. An interesting labour of love, but as far as dating's concerned, I'll stick to Lance's aHistory.).
In terms of proper, actual, cover-to-cover rereads, none. Simply because, quite frankly, I have enough books in my "to be read" pile to take, at a conservative estimate, a good couple of years if I don't keep adding to it. (Which I do, because I'm an insatiable purchaser of books.)
There were a couple I used to reread every Christmas - Pamela Sykes' Come Back, Lucy and John Masefield's The Box of Delights, but - largely because of the issue raised in the paragraph immediately preceding this one - I haven't reread them for a few years. I'd like to, though. See how it goes this year, perhaps.