As far as space opera goes: Hyperion Cantos by Dan Simmons, A Fire Upon the Deep by Vernor Vinge, The Night's Dawn by Peter F. Hamilton, Gateway by Frederick Pohl, Solaris by Stanislaw Lem.

As for cloak-and-dagger-esc drama, I've got less suggestions: the Malazan Book of the Fallen series by Steven Erikson and The Black Company series by Glen Cook would be what I can think of if you've already read ASOIAF. I'm currently reading the first book in the Kushiel's Legacy series, which is advertised as being somewhat like that though I haven't really encountered such drama yet.