I would kind of consider the stand alone books Black Man/Thirteen, Thin Air (two books, same universe) and the Altered Carbon trilogy by Richard Morgan "hard" sci-fi to an extent - and be aware that the TV series, while entertaining, butchered much of the political content in the books.
If you like the "Takeshi Kovacs / Altered Carbon" trilogy, you'll almost definitely like the "Greg Mandel / Event Horizon" trilogy by Peter F. Hamilton.
And they're not bible sized tomes like some of PFH's later space operas (some of which I own, but am too intimidated by their size to have considered starting the journey).
True, I was considering mentioning Hamilton, but it's been so long since I read those books - so wasn't quite sure if I'd call them hard sci-fi or not :)
