My Chem lab instructor, for giving back my quiz paper with TWO smilies written on it. One said "Yay!
" to congratulate me on my success in balancing a particularly difficult chemical equation. The other said "Ngek!
" pertaining to the joke I gave as an answer to the bonus question.
The smilies had me scared a bit, but mostly they made me laugh.
Oh, and I assign redox reactions. They are just sooo fun.