Maybe not serious sounding to a skeptic, but I see no reason why they couldn't be coming here and studying us as we study lower primates. Maybe there is something in our physiological makeup that doesn't make sense to them and they're trying to get a better idea as to why we even exist, because we don't make scientific sense to them. Perhaps they're looking for a way to subvert our independent will in order to enslave us and do their bidding. There's thought that they could've even been here back in the time of the ancient Egyptians, and that's how the pyramids were constructed... through slave labor, but not to the Egyptians but to their gods... aliens in the guise of gods that is. Ancient Egyptian, Mayan, Inca, Toltec, and Aztec ruins all seem to depict a sort of alien being... the concept of alien visitations doesn't seem to be that foreign to them, only they viewed it as visitations from the gods. Look at the crystal skulls that have been found... made of a single piece of crystal, depicting a head that is very large and oblong, much like we view the grey-type aliens in science fiction and popular culture. There is a model of a type of plane that was found in ancient central american ruins that when enlarged into a workable model that was an exact replica of the object, displayed perfect aerodynamic qualities and was able to both glide and fly (with an engine attached).
The evidence is out there, we just have to be willing to see it for what it is. Look at cases like Betty and Barney Hill... Betty described a constellation of stars pretty much perfectly from what her supposed abductors told her of their planet and solar system. The case of Travis Walton has a lot of corroborating evidence that goes along with it. What about the Phoenix Lights? How can they really be described outside of an alien visitation?
