New style vs old style
Having read sci-fi for the last 30+ years I've read probably every sub-category within the genre. Some authors/books stand out for me above all others:
Anything by the ubiquitous Asimov - obviously
The timeliner trilogy by Richard C. Meredith - rare classic
Anything by Iain M. Banks - obviously
Waging war in the afterlife by Shaun Othen - a neat take on religion!
Spinward Fringe series by Randolph Lalonde - good high tech series
Turing Evolved by David Kitson - a love story with a twist!
Other great masters of the genre:
Arthur C. Clarke, Nick S. Thomas, H. Beam Piper, Stephen Sweeney, Poul Anderson, Ray Bradbury and so many, many others...
There's so many good writers that I've read over the years, and probably many more that I haven't yet discovered, so I'll definitely try some of the recommendations here from other posters...