I mean, as far as quality goes, the standard stuff: musical prose, well-designed plot, complex characters, etc. What determines whether or not I became obsessed with a piece of fiction,, tho, is if I fall in love with one of the characters.
Discussion
Musical prose is something I don't think about often, but I do love it when literature has a poetic quality to it. One book like this that pops to mind is The Weight of Ink. There are passages of prose near the end that are just amazing.
It's not just poetic quality, it's also... Idk, it flows well. Good variety of long and short sentences, vivid, properly placed, and not overused metaphors and strong verbs, etc. I literally feel my muscles relax when I'm reading that type of prose (unless it's a high - action or tense scene that is).