I didn't see these listed, so if Q, my apologies. Anyway, two trilogies I've read over the last 5 or 6 years have really stuck with him, even though I've read hundreds of other books (thanks to Baen for the awesome free library and cheap bundles).
Apparently these are "hard scifi", although I had never heard that term until recently. Either way, they are some of the best character driven stories I have ever read. They are both near future stories that focus on the people and relationships, building up slowly but engagingly. They both start out with almost a post-apocalyptic colony vibe, the characters building a society/culture of their own. These were books that I just couldn't put down.
Rather than try and describe them, I'll just add links to the Amazon pages/reviews. The Rifters series is available free from Feedbooks, which was actually the only reason I gave it a shot.
The Rifters by Peter Watts (Starfish, Maelstrom, Behemoth)
http://www.amazon.com/Starfish-Peter.../dp/0765315963
(Available free at
http://www.feedbooks.com/book/974/starfish)
Mars Trilogy by Kim Stanley Robinson (Red Mars, Green Mars, Blue Mars)
http://www.amazon.com/Red-Mars-Trilo.../dp/0553560735