I think that using the term "aliens" is what puts people off. It makes people envision skinny green guys with giant heads and almound shaped big black eyes. Most people are going to say "no" to this question based on this assumption, or based on their fear of the unknown, or perhaps even their religious views. For many people if "God" didn't say he did it, then it can not exist.
Gem...I loved your answer...The truth really is out there!!!! And no I am not just "believing the lie"
Has no one here ever taken an astronomy class? Ever heard of the Drake equation? While it isn't anywhere near being exact...it is probably what Angie was trying to get at.
The vastness of the Universe is just something many people can not grasp. We look at things as having limitations and boundaries. Buildings are surrounded by walls, if you travel far enough around the world (because it is circular) you will end up where you began...why? Because there is a starting and stopping point. But the universe can not be looked at from this mentality. You have to shed your preconceived notions about how things are "supposed" to be, and try to get your head around the real understanding of how things actually are. In the "grand" scheme our tiny planet Earth is nothing.
Try to imagine one grain of sand on one beach by one ocean on the planet earth. Imagine being on the moon and trying to locate that one grain. Now multiply that by infinity. Hard to grasp isn't it? But just because you yourself do not have the ability to understand something so immense and profound doesn't mean it doesn't exist.
Do I believe in Aliens? As they are portrayed in our current culture....NO. Do I believe in life forms on planets other than our own...absolutely.