My first instinct was to pick Harry Potter but even with cheating and taking all seven they would not keep me entertained for that long because I can't help but rush through them everytime. (No seriously...it took me three re-reads till I did not binge-read the first three in one night anymore). LOTR is something I can actually read slowly and also a coupke of times because there is so much that I haven't discovered/already forgotten since the last time I read it.