Does Schlock Mercenary count as Hard Scifi? What about Freefall? They've both got FTL travel, and the former has other fairly miraculous technologies (like the matter annihilation plants and artificial gravity systems intimately related to them), but they're well thought out with the rational implications of them seen and discussed.
Novels
Blindsight, Peter Watts
Ventus, Karl Schroeder
Crisis in Zefra, Karl Schroeder
Accelerando, Charles Stross
The Lifecycle of Software Objects, Ted Chiang
Short Stories
The Island, Peter Watts
The Things, Peter Watts
Short Stories by Peter Watts
Divided by Infinity, Robert Charles Wilson
Crystal Nights, Greg Egan
Short Stories by Greg Egan
The Finale of the Ultimate Meta Mega Crossover
Three Worlds Collide