Sad to see Stanislaw Lem completely left out in favor of some obviously inferior books (Anathem!?). Also a curious choice for the obligatory Atwood novel. Surprised that Gravity's Rainbow was not on there- I'd put it near the top (maybe it wasn't "Sci-Fi" enough?)
Good to see Canticle for Leibowitz as well as a fair amount of Asimov and Dick.
I particularly like The Star Diaries, The Cyberiad and His Master's Voice.
If you want to read literature, choose something that will at least make you think better, not just dazzle you with future tech.
Could you elaborate?
Also, Pynchon's prose is very rich - I expect popular lists to be dominated by lighter fare.