I love the PureCSS portraits by Diana Smith (Cyan Harlow)
What gets me is how relatively few rules there are -- I mean, it's hundreds or thousands of lines in some cases, but it's not 10s of thousands. Besides, the rules use names that you can actually understand to get a sense for how the piece, as a whole, works together.
I just noticed the little skull accessory's eyes change with the character's :D