[ChrisV]

The Takeshi Kovacs series (Altered Carbon, Broken Angels, Woken Furies) by Richard Morgan is good sci-fi. I don't know if it's particularly deep, but it's definitely adult, if only because of the fairly extreme levels of violence in it, and I think he's a good writer. He has an ear for dialog, which is important in this kind of thing. They're detective noir/cyberpunk/military scifi thrillers. Altered Carbon is far and away the best, but Woken Furies is quite good too. I also recently read Black Man by the same author and it was good, less futuristic/cyberpunky than the Kovacs books, more a straight scifi thriller.