Dude, Teen Titans is awesome.
But yeah, there is a sort of general alien 'persona' that authors seem to portray. I think it falls more under the category of commenting on humanity than anything else, though. Visser One makes commentary about how Hollywood is the most influential place in the world, Elfangor notes that people sticking white cylinders in their mouths is ridiculous when it makes them seriously ill. Ax treats advanced technology as a "game" and wonders if Big Wheels are weaponry.
When you have a character that is on the outside of humanity looking in, you'll have similarities across the spectrum. Imagine if you were a complete stranger to Earth and you walked in on a bunch of bipedal sentient beings who spent half their time eating, half their time starving themselves, half their time killing one another and the other half in front of the television?
(and yes, to quote Marco, I know that is too many halves)
Similarly, I think that as an "outsider" you would find some aspect of humanity to become fascinated with. Food seems to be the most obvious, since there is such a VAST variety of foods, but there are other aspects to marvel at as well.
