Would aliens look like us? By "us" we mean humans on the planet Earth. By "aliens" we mean life forms from another planet. While statistics vary, many, many people believe that there is life in the cosmos. We are not alone. Just because we have yet to find proof doesn't mean that we are alone. After all, we have only managed to leave the Earth in the last 50 or so years. Earthlings (being the alien) have stepped foot on exactly one other body in the cosmos, our very own moon. We have robotic rovers and satellites that are exploring Mars.
In the grand scheme of space, this is like exploring less than all the cubbies in one desk drawer in a single office of one skyscraper of all the buildings on Earth (times an almost infinite number) blindfolded. Basically, we haven't been anywhere. We can look deep into space but we don't know much more than the information that we get from pictures.
We do have probes that are rocketing out of the solar system but the problem is, by the time they reach the next planet (say Jupiter) the technology is already seriously outdated. We (as a species) are almost completely ignorant of what life forms on other planets might look like. The best we can do is make guesses, which are often based on the extreme climates found on Earth.
There is a chance that aliens could look like us. Exactly? Probably not. They could have a humanoid appearance though. Think about the famous "grays" of Roswell fame.
There are many theories out there that are gaining popularity about how humans evolved on, or came to Earth. Of course the evidence for this can be interpreted in many ways. The fact that there is no solid proof one way or the other leaves the question still open for the heated debates. If humans are not native to planet Earth, or to put it another way, Earth was seeded with the life form that became the modern human, then the answer to the question could be yes. There very well could be aliens out there that do look similar to us.
One argument for this is the fact that humans really aren't actually built for this planet. Even though we need water, most of it on the planet is useless to us. That is useless in the fact that we can't drink it. Most of the Earth's water is salt water which is not what the human body needs. Another point is, our bodies aren't set up for the climate of this planet. There is a narrow band on the planet that has a climate that a human can survive without clothing, shelter, and other necessities. That doesn't even take into account the fact that we have no natural defenses (or abilities to hunt food) other than our intelligence. It almost seems like we weren't made for this planet.
While the first part of the article answered yes to the question, that is only with a very specific set of circumstances. The (probably) close to infinite amount of planets and moons that orbit stars gives you an indefinite number of possibilities for life. Even if we narrow the search down to species that are at our intelligent level or above, the possibilities are still incomprehensible. We have trouble understanding numbers that are that big.
Most aliens would not look like us. That could probably be taken as a fact (probably because as of yet, there is no proof either way). If we look in our own back yard, which is the planet we call home, Earth. Life takes root in places that a human would consider impossible. Little or no water, freezing water, boiling water, sulfur vents on underwater volcanoes, the list goes on and on. If life can survive in these "impossible" environments here on Earth, why not on other bodies in the Universe?
Just as the life forms take every conceivable shape, size, and form in these various places so would they on a planet (or moon) that is different than Earth. A life form that developed in a different atmosphere, under different pressures and temperatures would be completely different than we are. Even something as simple as a different mixture of gasses on a planet could cause the life form to be completely different.
There is an obvious pattern here. Unless the life form developed on a planet with the same history (geologically) in the "goldilocks zone" there is very little, if any, chance that they would look like us. The single exception is the before mentioned (yet unproven) theory that humans did not originate on this planet.
For the time being, all we can really do is make guesses that are more or less shots in the dark. Until we have developed the capability to explore other planets and moons (both in our "neighborhood") and outside the solar system, we won't really know the answer. That is of course unless the aliens decide that we are worthy of an introduction.
As of right now, the answer would be no, aliens would not look like us.