Abercrombie books. Read them in order, otherwise you will miss a lot.
Try American Gods by Gaiman as well. Its a standalone.
I hear Acacia by David Anthony Durham is also good, and people compare it to ASOIAF. Haven't read it though, so take this with a grain of salt.
For sci-fi, I am Legend by Richard Matheson is pretty short, and pretty dark. Damn fine book too
