Just thought I'd see who you like. I'm a die hard sci-fi-er.
Roger Zelazny tops my list, his Amber series is my all time favorite series. On the whole I prefer his early work (This Immortal, Dilvish the Damned), rather than his late collaborations....when he paired with another author I think he put out some garabage (especially his posthumous work).
Roger is closely Followed by:
Orson Scott Card
and Arthur C. Clarke
I am always looking for good Sci-Fi authors to read....so if you have some that are noteworthy...please share