Mine are the molecular orbitals of hydroxylic acid, which if you haven't guessed already is...
...water...
For those of you that don't know, molecular orbitals are basically a bunch of fancy maths stuff used to describe the position of an electron within a molecule, since due to Heisenberg's Uncertainty Principle, you can't determine the exact position or momentum of an electron at any given time. Both "bonds" and "lone pairs" are actually molecular orbitals instead.
I won't go into it any further since it's really complicated and unnecessary for me to sperg about.
Galvatron from Transformers: Superlink. Or Transformers: Energon, if you prefer.
I chose that one instead of using a picture of, say, the original Galvatron, because he was voiced by one of my favorite voice actors, David Kaye (who famously played Megatron in Beast Wars)
Originally it was the drawing Chris did of an angry CWC I found on the anger CWCki page (I think?) I just switched it to a drawing of Godoka from Puella Magica Madoka since you know.. Magica.