This guy, and that guy.
Very humanoid. Along with those are all of the people from BattleStar Galactica and Firefly, aliens from Star Trek and Star Wars, Doctor Who, etc. We seem to like the idea of humans exploring the universe and finding other humanoids. But those are definitely not the only types of aliens the human mind has invented.
There are much weirder aliens...
And then you have scary.
The blue aliens are scary because they seem to be studying us... and yet we can't understand them (Stargate Universe).
There are of course hilarious aliens...
(Men in Black)
And let's not forget the metal aliens...
And the all-famous Cybermen (Doctor Who), not technically aliens, but creatures invented by humans (and made out of humans) usually brought in from another universe or from the future.
And we wouldn't want to leave out a Transformer.
I'm also going to throw a nice alien in, for good measure:
These aliens can morph into anything you want them to be. They are in Star Trek, Next Generation.
And finally, I'm going to leave you with a taste of one of my favourite aliens - the Clockwork Aliens (Doctor Who).
Now, these are probably better classified as alien robots, as they seem to function under only one directive and have no willpower to do otherwise. In that sense, they are slightly terrifying, because they're taking people's internal organs to make their ship function properly, but they're so beautiful! And imagine they weren't evil killing machines - they would make awesome butlers.
This is far from all of the aliens in the fictional universes of Earth, as it leaves out all books and about a million movies and other TV shows, but it's a start.