"Ghostface" is the a rather deep, scratchy and intense voice that's showed up a few times. The only instance I can quote off the top of my head though is the Sex Is Personals episode:
"JOSH FROM THE FRAT HOUSE ON FIFTEENTH— I'M PREGNANT"
"You do that voice really well."
"THANK YOU"
The one that reminds me of Mr Burns is from The Aces and the Cakes, when one of the ridiculists is reading the very long, rambling post of a college-age asexual who doesn't know why two people would sleep in the same bed.