I'm not one of those people who does a lot of rereading; if I read a book once, even if I like it, I don't generally want to read it again. Because you have to put a lot of hours into reading a book the first time and, well, there's a lot of other good books floating around in the ether/library/bookstore that I haven't got to yet. Besides, I already know everything that happens so there won't be any surprises.
Yes, I actually have a list of books I've been meaning to get around to reading. And yes, it keeps getting longer and longer.
Of those I have read more than once, there's a few I consider worthy of being read again (and maybe again and again ... on a yearly basis or something). One of those would be Kalpa Imperial by Angelica Gorodischer because, well, it's a really weird book (meaning you have to read it a lot of times to understand everything), offering multiple narratives and giving the sense that each one means nothing and yet a whole lot at the same time. If I read it once more, maybe I'll figure it out. Also, the author is from Argentina and so the book was translated into English by Ursula K Le Guin. Which on its own is pretty cool.
Second would be Robin Wayne Bailey's take of Fafhrd and the Gray Mouser (two of my favorite characters): Swords Against the Shadowland. I love the original stories by Fritz Leiber, too (have read many of them more than once), but for some reason this one sticks with me. Maybe because it's more in line with contemporary book/writing styles? I don't know if it's that or the ever-tacky reader's assertion that "I could visualize everything exactly as he wrote it" (an assertion that proves tacky because of course when the author wrote about a red table the reader visualized a red table ... etc). Or because he channeled the characters as if he'd invented rather than borrowed them.
I don't know what it is, but in both cases even though I know everything that happens, even to the point that I remember some snippets (or close enough) of the writing, I wouldn't mind reading them through again. I think all books should be such a pleasure to read that you want to read them over and over--and of course every author probably thinks so, too--and yet, if that was true, I'd never get around to reading a new book, would I?