Alien invasion and exterminating the humans is mostly in the movies. Alastair Reynolds is the only author I can think of that has written books about xenocidal alien invaders that are attracted by human activity. Even in War of the Worlds the aliens found us first before we even left the planet.

My personal opinion is that we are alone as an intelligent, technological species. There are simply too many factors precluding the evolution of similar species. Even on Earth, we didn't evolve first. The dinosaurs ruled the Earth for hundreds of millions of years, preventing primates from evolving significantly different survival tactics from rodents (small, quiet, discrete, nocturnal, burrowing, or tree dwelling). It wasn't inevitable that the dinosaurs went extinct, that a really big comet hit and caused global rather than regional destruction. That constraint of a dominant predator may still exist on most life-bearing planets, preventing the emergence of intelligent species.

An interesting question one might pose is... What makes primates more intelligent than, say, rodents, or the predators that fed on them for so many eons?