Dammit I thought this was a topic about the movie Aliens, not enough people talk about that movie being that it's the best movie ever.
If you don't think some form of alien life is out there and that we're some miracle and that the odds are impossible that life could exist elsewhere you're quite foolish.
There's more planets in our galaxy than there is sand on our planet, and we're a pretty SMALL galaxy out of countless. There's any number of places life could be, and the whole argument "life needs very specific standards to live on" is WRONG. We've found life thriving in the bottom of the ocean with crushing pressure near scorching hot volcanic holes, if that's not enough how about life, LIVING ON NUCLEAR RODS? There's life in rocks, there's life in the sky, underground, in dark rooms playing WoW all year long.
There IS life out there, it's impossible for there not to be the odds are heavily stacked against there not being life outside this planet. Is it intelligent? There probably is some form of intelligent life and probably not so intelligent just like here.
Why haven't aliens visited us? Numbers of reasons, if they can travel the galaxy why would they come to earth? Do you stop by an anthill on the way to work and try to explain how your ipod works? No, we're a pathetic little species with very little understanding on anything. Humanity isn't even a second on earths clock, an infant species that is still growing and learning. Hell there's still people hating each other because of the amount of melanin in their skin, why the fuck is some big eyed green dood gonna come by here? To get shot in the face because he's different?
Point is, there's life out there, I just hope that in my lifetime we see some of it no matter what the size. Just as long as they're not here for our resources.