Billy Mays fully realized what a Large Ham he was in his commercials, and was more than willing to make fun of himself for it. This made his on-screen persona's "ALL YELLING ALL THE TIME" policy strangely hilarious.
In an interview he did with the Washington Post he describes how he was stuck at home recovering from a hip operation and forced to see repeated commercials starring himself. He was getting sick of his own voice!
Lampshaded in the advertisement for Pitchmen, a show starring Billy Mays and Anthony Sullivan about pitching product, which of course featured Billy Mays in his on-screen persona.
Anthony Sullivan: There's more to selling than just the yelling! (points to Billy Mays, who looks insulted)
Awesomely parodied by himself here, as he shows you how pros order food at McDonald's.
Also parodied in Horrible Histories.
Shouty Man: I'M A SHOUTY MAN, AND I'M HERE TO TELL YOU ABOUT...
Roni Lynn Deutch.
Barry Scott, known in Australia as BAM! AND THE DIRT IS GONE! Apparently the only difference between American and Australian audiences is the number of letters we tolerate in our product names. He also advertises on British television, to the extent that jokes are made about that advert on Mock the Week.
He's in New Zealand too.
Car dealership ads are infamous for this:
Gesswein Motors in Milbank, South Dakota! That guy used to be at LEAST as bad as Billy Mays in his commercials on the local CBS station.
There's also Tarbox Toyota of North Kingstown, Rhode Island, whose radio and TV advertisements star the dealership's owner, Ed Tarbox, known throughout Southern New England as someone who's voice will wake you up from a deep sleep at 2:30 in the morning.
Billy "Huge" Fuccillo, bane of upstate New York, south-eastern Ontarians, and recently Southwest Florida.
Another infomercial maven who lacks a "quiet" mode: Tony Little, hawker of plenty of exercise machines. Lampshaded when one of the girl hosts in his infomercials says "Can you calm down?" "NO!"
Matthew Lesko, a strange man who wears question mark suits and appears in TV commercials advertising his book on government programs from which people can get money. He needs decaf, and he needs it badly.
Reason TV came up with a good use for him and his style once, though.
A TV advertisement for Staples (an office supply store) involves a man shouting "WOW! THAT'S A LOW PRICE!" at every item on the shelf.
Clerk 1: How many products do we carry? Clerk 2: Over seven thousand.... Clerk 1: ... I'll get him a cart.