GLaDOS may not be human, but she's an incredible character nonetheless. She delivers her lines with such wit, sarcasm, and dark humor that we just can't stop laughing right along with her. Even though we're the ones she's laughing at.
Honestly, if we're to find ourselves as test subjects in a series of sick experiments, there's no one we'd rather have pulling the strings than GLaDOS. We may hate her, but we just love hating her so much that we actually kind of like her. And she sings.
It takes a special kind of girl to be able to keep up with all of Nathan Drake's schemes, but Elena Fisher is that kind of girl. In fact, at times, she's almost as unpredictable as he is. The Uncharted series has always done an exceptional job of presenting incredible female characters, and Elena is probably the best example of this. She's such a strong character, but so brilliantly human; we can't blame Nate for always running back to her. Come on, Nate, just don't screw it up this time.