Well, yeah. Even if they did look exactly like us, the culture of a race from a different planet could be completely different and interesting. I just like designing funny-looking creatures and giving them sentience.

There are so many different answers to this question. (I feel justified posting a full opinion again because the last time was a year ago and this is still so interesting.)
The main question is, would God create any other race in His own image besides us? Secondly, would he put other races or other humans (either way) on any planet besides Earth?
My personal opinion is that, given the size of the universe, answering with a flat no would be a trifle arrogant of us. I mean, it's possible that we are the only sentient race in a universe filled with billions of galaxies each containing hundreds of stars, but that seems unlikely. Maybe God created all that stuff for us. But maybe we're meant to share it with all manner of alien beings, who maybe look and think like us, or maybe don't. Or maybe He has other unfathomable purposes for the rest of creation that we'll never find out about (at least not in this lifetime).
Tangentially related to this topic: my Dad has a theory that the rest of the universe may be filled with other living things, but we're cut off in a bubble of vacuum because we sinned.
I like how, in sci-fi, we're free to explore all the maybes. X) I am actually planning different stories and universes exploring all of these questions; some with only humans, some with lots of aliens and they think like us, some with only a few aliens and they don't, some with nothing beyond Earth, some with Earth being relatively insignificant. It's so challenging looking for where the truth fits in each possible story; I mean, you ask God, "What's possible beyond my own tiny level of experience?" and He's like, "Oh, just about everything, kid."
I'm curious: What kind and amount of aliens are the rest of you using in your stories (the question of whether it's actually possible aside)?