I voted 'foundation' although I don't like it. Couldn't read it. However plain sci-fi is my genre of choice so while I enjoyed some of the other books more than 'foundation', it's the genre that counts. My faves would be anything by Heinlein or and of the straight sci-fi from Orson Scott Card (such as the Ender series). I'm currently reading 'Enchantment' by OSC and reasonably enjoying it. I figure if I like his other stuff I should at least try all of the fantasy. I didn't like Alvin Maker at all! Oh, Greg Bear is another fave, once again the straight SF like EON and Moving Mars.
in reply to The sort of fiction you're most likely to find me reading: