Hilariously, GLadOS is ... actually much more relatable, in that she...well I hope this isn't spoilers at this point?
She was mostly kind of originally a human, and is actually at least capable of empathy, she has moments where she seems to express at least barely, a sense of concern for Chell's wellbeing.
Sort of.
lol
She also gets stuck in a potato.
SHODAN on the other hand is literally 'fuck you, pathetic worm, I am God.'