the Milky Way galaxy has Hundreds of Billions of Stars, each with their own Planets circling them just as our Earth Circles Sol.
then, even further out are more Galaxies with even more Stars and planets.
as such, it is close minded to say that there is not life out there somewhere, so yeah I believe in Intelligent life being out there somewhere, especially with all the new "habitable planets" NASA has discovered over the past few years...
But as for "Little green men abducting our Cows (or Elvis)", or anything like the Aliens in Mass Effect for example.. Haha, nope, don't exist..