The thread that loosely ties this massively popular sub-genre together seems to be using imaginary worlds, alternative realities, parallel universes, space exploration or potential changes in technology to illustrate aspects of our own existence often in the form of a moral lesson for our own world and own times.
Whatever definition of sci-fi you prefer, I think we can all agree it covers an enormous range of the arts and thereby encompasses both genius and dross, so I'm curious to know what bits of sci-fi float your boat?
The first "proper" sci-fi book I read - and bearing in mind that for the first 16 years of my life I'd been fed a diet of Torchy the Battery Boy, HG Wells classic films on the telly, Gerry Anderson's Fireball XL5 etc, Daleks and Quatermass and the Pit - was Ray Bradbury's "The Illustrated Man".
A collection of 18 short stories - some simply moralistic and others absolutely brilliant in concept - all based around a central story about a man who had been tattooed by an alien witch and when folk looked at the tattoos it gave them visions of worlds where things happened that had an implication on their own lives. The tattoos were a curse - as those who looked at the illustrated man invariably ended up hating him for showing them the alternative reality.
This book is by no means a challenging read and I would recommend it as something to leave by the loo. - and not as a standby in case you run out of loo roll.
A few years after I read it they made an appalling film of the book - well 3 of the stories in it - starring Rod Steiger and I would recommend avoiding that at all costs.
Any sci-fi recommendations?