If I had to pick a favorite commercial, it'd be for that chain of electronic stores in in the New York area called Crazy Eddie. They were around late 70s/early 80s, but, are they good or what? In the commercials, this announcer Jerry Carroll was practically hyper, announcing sale prices at all Crazy Eddie stores, mentioning that they aren't/can't/won't be undersold, also mentioning you can find the lowest prices around, take them to Crazy Eddie, and he'll beat them. In every commercial, Crazy Eddie was always referenced as the 3rd party. The lasting mark was the famous tagline, "Crazy Eddie - His Prices are IN-SAAAAANE!"
http://www.youtube.com/watch?v=wZXoe0IG4Gc
http://www.youtube.com/watch?v=n_2QW1oZiAQ
http://www.youtube.com/watch?v=dpYFGfTBgcw
http://www.youtube.com/watch?v=-XMEpi7zbc0
http://www.youtube.com/watch?v=v-E63czDofo
And some crazy outtakes...
http://www.youtube.com/watch?v=WKvYSSVBYdM
http://www.youtube.com/watch?v=wZXoe0IG4Gc
http://www.youtube.com/watch?v=n_2QW1oZiAQ
http://www.youtube.com/watch?v=dpYFGfTBgcw
http://www.youtube.com/watch?v=-XMEpi7zbc0
http://www.youtube.com/watch?v=v-E63czDofo
And some crazy outtakes...
http://www.youtube.com/watch?v=WKvYSSVBYdM