A friend mentioned yesterday that he would be interested in knowing what order I would recommend reading Ursula K. Le Guin novels. That got me thinking, and so I decided, while I'm at it, to do China Miéville as well. I think familiarity with both of these authors is crucial for SF study these days.
I think that The City and the City and Un Lun Dun both serve as excellent introductions to Miéville's work, much more so than the Bas Lag trilogy, though it's important to get to that fairly soon on. I had internal conflict over where to put King Rat. I think it's crucial to understanding Miéville as a writer, but he executes the same concepts so much better across his other works. (King Rat was his first novel.)
A Wizard of Earthsea is not only great introduction to Le Guin's work, it's also a great example of how a young adult novel can be simultaneously accessible to teens and intellectually sophisticated. After that, I think that The Left Hand of Darkness and The Dispossessed are together the best introduction to the Ekumen, Le Guin's pan-galactic federation of worlds. I think that her early Ekumen novels, Rocannon's World, Planet of Exile, and City of Illusions are underrated and deserve much more attention than they receive. City of Illusions is particularly good.
Putting this post together has reminded me that I had an "Introduction to SF" curriculum on my old blog. I should dig that up and re-post it in the near future.