I have a soft spot for GLaDOS. I think that perhaps (like HAL from 2001: A Space Odyssey), her apparent psychosis is her only way of coping with the situation her creators put her in. In an ideal world, we'd be friends ^_^
This started out as a rough sketch of mim's that she didn't like, which I offered to finish. It's been exciting to see a different style emerge, and I think this might be my favourite Portal fan art that we've done to date.
There's also an uncoloured version to check out/colour in if you like.