Ximon (Simon) because he is Facial Turd
Quadratic formula (the solution to ax^2+bx+c, which gives migraines)
This thread has gone a long way from belugawhale to quadratic formula!
Chocolate chips (in the formula for making cookies)
Antimatter (Makes the largest explosions per volume of material)
Strange matter (This is also a form of matter, like antimatter)