Iain M. Banks - State Of The Art. Culture arrives, takes a look at earth, recoils in horror, considers whether to contact, observe or simply blow the place away. Decides on leaving us to it, buggers off.

The Gap series which has no good humans in it AT ALL. Or aliens for that matter.

Theres another series of stories, which no-one has yet given me the name of, which has humans as the mindless thugs of the universe. Everything else is clever, we do the thumping.