Do you think there is life, intelligent or otherwise, that exists on an exoplanet somewhere in our galaxy or perhaps another galaxy? Why or why not?

It is certainly possible that life, intelligent or otherwise, exists elsewhere in the universe. Researchers typically begin their search for life in the universe by looking for solar systems that are similar to ours. In our solar system, planet earth revolves around the sun, a massive body of combusting gas, due to the gravitational attraction between the Earth and the sun. Researchers postulate that there is something very special about the mass of our sun and the resulting gravitational force that holds our planet in an elliptical orbit. By looking for stars that we estimate are similar to ours, we are able to search for planets within those solar systems that are similar to ours; in fact, we have already found several solar systems similar to ours that have what appear to be habitable planets. In the grand scope of our infinite Universe, it is certainly possible that life can develop, just as the way we have.

This is an excellent question that is illustrated by a theory called Fermi's Paradox. Here the law of large numbers is pitted against a lack of evidence of extraterrestrial life. Or to put it more simply: if the universe is vast in space beyond comprehension, with more planets and stars in it than there are granules of sand on the beach, then it stands to reason that there are other planets similar to ours however unique we may think earth is. The paradox is that despite the law of large numbers dictating the extreme probability of much more extraterrestrial life, we have no evidence for it.
This could be for many reasons it is possible that the vast distances of the universe serve as barriers to the advancement and resulting travel of life. Perhaps there are many alien civilizations similar to ours in some ways but we are all to far away to reach one another. After all humanity occupies a pretty small amount of space and time in the universe. We are far away and have not had the means for attempting or recording extraterrestrial contact for very long in the grand scheme of things.
There is also the possibility that alien civilizations are aware of us and have decided to not contact us intentionally for a number of good reasons.

I do think life probably exists on another planet. There are hundreds of billions of planets in the universe, and it seems against all the odds of probability that the Earth is the only one of them to contain life.
I also tend to believe in the idea of life on other planets because NASA does and is spending money to try to locate life beyond earth. NASA's Kepler 2 (K2) mission is designed for that purpose. Through it, NASA is searching the cosmos for signs of life and a civilization on a planet other than our own. If the country's best scientists think this is a worthwhile project, I am not going to disagree.
If we accept that life evolves scientifically from the right mix of chemicals, it is hard to imagine ours is the only planet to get the mix exactly right. After all, the planets all come from the same matter created in the Big Bang. On the other hand, if we reject the scientific hypothesis of a Big Bang and believe God created life and called it good, it stands to reason he would spread his gift beyond our lone planet.