For me:
The Superior Alien Race that looks like Humans
Earth is home to a vast number of species. Only one of them looks like Homo Sapiens.
Now, imagine a species that looks completely identical to Homo Sapiens has evolved on an alien planet.
Identical, no, but humanoid I can believe.
Here's why.
Humans have evolved to be the shape we are because it is the most efficient for what we do. We don't have tails because we had to run a lot, and they got in the way and slowed us down. We have hands and opposable thumbs so we can work with tools. The structure of our heads is such that our brain could develop. Our eyes face forward because we needed to be able to see for long distances ahead of us.
An alien species might have different circumstances, but generally if they've achieved a level of intelligence like or better than ours, they will have been a species that uses community hunting or gathering strategies to survive, is highly mobile, and can manipulate small objects. Without that last capability in particular, they'd never make it to space, or at least it would take them tens of thousands of years.
But then again, there are plenty of different ways that an animal can handle small objects, and we don't know that intelligence can't spring up in entirely different places.
I would be super surprised though if dolphins or elephants ever made it to space, even if humans never came around for some reason or other.
I'm just saying chances are greater that whatever it is, it's bipedal with hands and a somewhat humanlike head
