Stranger in a Strange Land
Childhood's End
Dune
Lord of the Rings
Flowers for Algernon
Earth Abides
Fahrenheit 451
Lucifer's Hammer
Man in the High Castle
Alas, Babylon
On the Beach * - I know, that's eleven, so sue me.
I tended towards the apocalyptic scenario's, which may seem a bit maudlin, but the stories not only showed man at his worse, but also portrayed characters with incredible tenacity, courage and fortitude, qualities which could only inspire a sense of hope in the reader. The list could have easily been twice as long, as I practically devoured science fiction when I was younger, but no one else would have been able to list their favorites.
Magikman