http://en.wikipedia.org/wiki/Made-up_wo ... e_Simpsons
Did you know that "d'oh" is so entrenched in pop vocabulary that it was added to the Oxford dictionary in 2001?

Wikipedia's explanations and etymology of the show's terms are generally more detailed than those in Oxford though. "Craptacular" (opposite of "spectacular"), "m'eh" (an interjection expressing apathy, indifference and boredome") and "retirony" (which would represent a cop getting shot three days before retirement).
The article explains that, although people invent words all the time, they usually are not as broadly adapted and lasting as words created by producers of tv programs like the Simpsons.