billy mays
Spokesperson for:
Oxy-Clean
OrangeGlo
Ding King
5 in 1 Ladder
Kaboom
FoneFree

He yells just about everything he says to give emphaisis and look like an asshat. Although you got to hand it to him, his panic-attack inducing rages make you listen to his pithy sales pitch. In one sitting, an hour long 
Oxy-Clean segment, I heard Billy Say "Look at this!" over 47 times! He was poppin them out like he had tourrettes! Not to mention I heard all about the "Super Shammy!" he includes with his gayass product.

Besides Billy, the only other annoying person is the lady for the Grip n Flip commercials...
"Look at this!"

"SHIT STAINS ARE NO MATCH FOR THE POWER OF OXY-CLEAN!"

"KABOOM!"