not makeup, but the worst smelling cosmetic product i've used is Dr. Brandt's Pore Effect. it's the smelliest (think insecticide & lemon cleaner) thing i've use, but b/c it works, i continue to use it.
as far as names go, i can only think of the crazy names for NARS cosmetics. i love his stuff, but some of the names are outlandish. the only one i think is wacky is Deep Throat.