I have a long list of books that I mean to read. I've just started one of them (Philip K. Dick's The Man in the High Castle, if you want to know). The last one I read was John Wyndham's The Day of the Triffids.
I'd pigeon-hole it as SF/horror that is disarmingly well-written — Wyndham's skilfull use of language emphasises the stark environment he describes.
I won't give too much away (follow the link above to Wikipedia for all kinds of detail), but I'll make this observation: writing almost 60 years ago, Wyndham hits many of the now well-known post-apocalyptic tropes (did he originate them?). Reading Triffids, I found myself remembering its echoes in 28 Days Later, Cormac McCarthy's The Road, Land of the Dead... all kinds of others. I found it a pleasure to read a tale from before many of its key points became hackneyed.
There's a paranoia that runs through the novel that at first felt a little dated, but quickly seemed to me to take on a new, modern relevance. No-one's quite sure where the Triffids (man-eating, walking plants) came from, but genetic splicing by foreign government scientists is implicated. The disaster that leaves humankind vulnerable may even have been man-made, too.