For me, aliens must make sense. There has to be a reason they are the way they are. Humans evolved to fit Earth, and I imagine aliens would evolve to fit their homeworld. I don't like when aliens are portrayed as overly Human, but I don't like when they portray them as monsters either. Intelligent life is likely going to be more similar to us than it is different. They will likely be a social species, with some form of communication and a structured society. It's likely they will use verbal communication, as that's a much more effective means of communicating over long distances. Hormones, bio-luminescence and other non-verbal communication methods are great for conveying meaning across very short distances but imagine, however, if you were trying to tell a friend when it's safe to cross a busy street using only a spray bottle filled with a specific perfume. It'd be nearly impossible, as the scent would be blown away before it ever reached them. Now imagine trying the same task with a flash light, at noon, without a cloud in the sky. Yelling at them is much easier. Will their speech be something we could mimic? Maybe, maybe not. But with time might come understanding. Now the reason most Sci-Fi takes the near-Human route is simply that Humans have a hard time accepting something that is scary and grotesque. The "uncanny valley" means the aliens need to be almost Human, but not so Human that it makes us uncomfortable to think of them as aliens. So they add horns, and head tentacles. The movie Aliens, on the other hand, goes the survival horror route. The Xenomorphs in those stories are almost demonic. They have these large, elongated heads, a mouth with another mouth in it, exaggerated extremities and a spear for a tail. They're intended to evoke fear instead of wonder. I'm not a fan of the Aliens or Predator movies. I am a huge fan of Star Wars and Mass Effect. But I don't think either one is necessarily better than the other. They both take very different, but still viable, approaches to what aliens might be like. They both have issues with consistency, and they both have things in them that I don't like. Of course, you seem to be forgetting the Big Dental Patient who was extremely Human-like and the fact that he sent a distress signal that the Humans could understand and follow.