Alastair Reynolds "Revelation Space" series is fantastic. He also writes some great stand alone pieces (House of Suns for example). He is also quite strict about being hard sci-fi (no faster than light travel for example).

Also The Culture series by Iain M. Banks is pretty amazing but tends to be multiple independent stories within the same universe. He is also much softer on the science (quite a lot How does it work? Quite well thank you descriptions).