In James Cameron's Avatar, we're introduced to an alien race that we immediately take to: the almost-human Na'vi. But sympathizing with slightly-different people is easy. Here are few examples of sci-fi giving us truly "alien" aliens.
It's a common pet peeve among sci-fi fans: why do aliens always seem so undeniably human? Shouldn't a strange new consciousness from a far-away world seem more alien? And not just in looks - we've written about human-looking aliens before - but in motivations and behavior as well.