http://en.wikipedia.org/wiki/Gay,_lesbian,_bisexual,_and_transgender_characters_in_video_and_computer_games
Samus isn't a lesbian, actually. I'm a pretty big Metroid afficionado. If you've ever played Metroid Fusion, there's a strong romantic suggestion between her and her CO, Adam Malkovich. Through much debating and prying of Nintendo and its fan-base, we've established that there was, in fact, romantic tension between the two, although nothing ever came of it. It would be hard to have normal social behavior around humans when your parents were killed as a baby by a big pterodactyly thing named Ridley, then being raised by bird people, named Chozos. Here's the images from the Fusion Gallery that shows all that stuff and more:


This isn't really related, other than being a cool Samus thing that someone made:

I have a sneaking suspicion that Mario's gay. He constantly saves the princess, then just goes home without trying anything with her. Not only that, but he lives with these tiny, spotted people that look like walking penises.