Trek aliens vs. SG aliens
I happen to think that Star Trek has the very best aliens of all time, at least as far as looks go. It's true that Star Wars has some very authentic, original kinds of creatures, but I'm a huge fan of more "human-oid" peoples for some reason. There are so many of them, ranging from the Klingons to the Vulcans to the Malon. Babylon 5 is also known to do this, only usually with more effort placed upon the creation of their species, make-up-wise.
I don't mind the ridges, I think they add variety. I mean, ask yourself why so many fans of StarGate SG-1 watch that show (not to put down a truly excellent sci-fi masterpiece in the making, since I watch it and love it myself!)? In SG-1, though, there are no "species" such as Cardassians. Rather, almost everybody in that show aside from Asgard and a few others are all members of the Caucasian group of the human species (Teal'c accounted for)... regardless of what planet they came from. But SG-1 does do a magnificent job culturally-speaking.