I have a favorite from when I was a kid--for a rather quirky reason, but I cannot verify if the reason is true...
I'm not sure if the commercial is still around, but when I when I was a kid they had a commercial for Park's Sausages both on TV and the radio. In the commercial, a young boy would yell: More Park's Sausages Ma!...please.
I have this vague recollection that at one point, in the actual commercial the boy would yell: More Park's Sausages Ma!
The way I remember it, there were complaints to the company by parents from all over because their children immitated the boy in the commercial and the parents were upset that their children were learning bad manners from the commercial--so in order to keep the successful commercial and keep parents happy, they added 'please' at the end.
Like I said, I don't know for sure if I'm right, but that's the way I remember it--and because of the quirky story behind it, it is a favorite commercial of mine.
(even though I've never tried the product)
Similarly, my favorite movie is The List of Adrian Messenger--because it has a peculiar quirk to it.