I'm currently a couple of hundred pages into Remembrance of Things Past by Marcel Proust (translated from the original A la recherche du temps perdu by Scott Moncrieff). It's a bit of a mammoth so it'll probably keep me occupied for a while.
So far I'm quite enjoying it. There are already quite a lot of characters to keep tabs on, that Proust fleshes out as he hops backward and forward in time -where I am now, he's reminiscing about his childhood holidays and the people in the town they stayed at.
The sentences are often really long and peppered with commas, so that sometimes I've had to reread them to make sense of how the clauses relate to each other.
I really like the sort of long cerebral tangents he goes off on, talking mostly about the nature of memory.