I like my scifi like I like my men.
I consider Vinge's
A Fire Upon the Deep and
A Deepness In the Sky to be the epitome of hard scifi. It is a complete universe based on fictional physics. That sort of thing doesn't write itself. It takes thought, planning, and a basis in real physics.
But it has talking puppies and an immortal space pirate.
That doesnt, to me, make it fantasy. The science overwhelms the fantasy.
Thoughts?