The problem with reading fiction is that there is a limited number of plots, and I’ve read them all many, many times, in so many combinations and permutations that I invariably think, “Déjà vu all over again,” when reading a novel. Characters, descriptive narrative, and minute plot variations are the interest points I read fiction for anymore. Well, that and a writer’s deftness (or lack thereof) with a story arc, etc. *shrugs* There’s enough left to feed the addiction. Re-reading exceptionally well-written fiction is quite often much more interesting than most new material available.
Non-fiction? Different criteria in many ways.