A fan of SciFi, tending towards space-opera. I like writing lists, so here are some authors I can think of:

• Pulp atomic-gollygosh-gee-whizz-1950s-nuclear-family authors like A.E. Van Vogt, E.E. Doc Smith
• Nice writing: Cordwainer Smith, John Wyndham
• Clarke, Asimov, Vinge, Peter F. Hamilton, Charles Stross
• Greg Egan, because he deserves a bullet-point all of his own

Every idea I put in an answer probably came from one of these authors originally.

I don't so much like fantasy and magic universes. Handwaving is great fun, but I prefer it to be 'technobabble did it' than 'a wizard did it'.