The most relevant example to this board, I suppose, would be Wheel of Time. Anyone who's even only done one reread will agree that there is a TON of stuff that you only see and understand on a second pass. I think WoT actually works best if you read it, do a reread, take 6 months or so off as you peruse theory boards and are convinced by Cannoli how much Egwene sucks, and then do a third readthrough.