Some Varieties of Science Fiction

Hard SF
Mission of Gravity, Hal Clement (1953)
A Fall of Moondust, Arthur C. Clarke (1961)
"Soft SF"
The Left Hand of Darkness, Ursula K. LeGuin (1969)
The Sparrow, Mary Doria Russell (1996)
Monitory SF
The Time Machine, H. G. Wells (1895)
1984, George Orwell (1949)
Sociology of science
The Gods Themselves, Isaac Asimov (1972)
Galatea 2.2, Richard Powers (1995)
Alternate history
The Man in the High Castle, Philip K. Dick (1962)
SS-GB, Len Deighton (1978)