I'm shaving down my list by guessing at what might make a favorable reading impression to the people frequenting our board. I'm also guessing we have a fair number who want to try their hand at some creative writing of the genera trash variety, and are looking for more modern works to study. These are all personal favorites.
Creatura by Paul Lucas. Post-apocalyptic furry fiction. The characters are radically re-engineered humans, done so in a final act of desperation to carry civilization past the end of the world. Mostly, they understand their own past and why things are the way they are. This keeps the story well grounded, and the characters easy to identify with, skirting by the detrimental weirdness and general stupidity to which furry fiction is associated.
The Quiet American by Graham Greene. A story wrapped around personal and political murders, and how horrifically wrong all this can be above and beyond all the other wrongness in the world. This theme is a specialty of Greene's. One of two examples of the kind of novel I wish I could write.
The Human Factor by Graham Greene. Again, Greene builds a story around one single awful murder, excused as an act of national security, and with no need for more violence to tell the tale. Has something of a contemporary echo too - think Edward Snowden.
Inherent Vice by Thomas Pynchon. Hard-boiled hippy detective noir, anyone? Like Greene, Pynchon can write cinematically when he wants to and to great effect. This is the second of two examples of the kind of novel I wish I could write.
Foundation and Empire by Isaac Asimov. Second in the trilogy. Obviously, you should read the first as well, but this is the star of the show. A good study to see how much can be done with a short serialized format. The second part has an interesting parallel with The Lord of the Rings - the distantly menacing unseen Dark Lord here known as The Mule, and his own grotesque creation as the key to his undoing in the form of Magnifico Giganticus, a diminutive wayward court jester.
The Wardove by L. Neil Smith. Some people go for Ann Rand's works. Fine, and far be it from me to say how one should write, save that I can't stand Rand's style and construction of a novel. Smith is a good example of how to mix political thought and philosophy into a story. A pop music industry wartime murder mystery in space.
Grendel by John Gardner. Another good example of how to mix philosophy into a story. Modernized retelling of Beowulf from the point of view of the monster.
I could go on and on. Instead I'll finish up with this:
The Seven Who Fled by Frederic Prokosch. This shows why prose writers should study poetry, even without the intention of becoming poets themselves. Vivid engrossing travels through strange and remote lands and peoples, with a touch of religious symbolism thrown in. His chatty personification of Satan is the best I've read outside of Milton.