I’ve updated the original post a couple times. Also a couple emails:

Hi Jonah,
First, Max Headroom was a (brilliant) made for British t.v. movie long
before he was a prop for Coke.
Second, allow me to vent about the Geico cavemen. The ENTIRE PREMISE of the
commercial is that the website is so easy to use that even cavemen can do
it. Yet in ad after ad we see the cavemen as highly sophisticated. They play
the piano in a poshly decorated apartment, order dishes with mango chutney
salsa, hold upscale parties in urban loft environments and even consult
therapists. Given the high level of intelligence and culture that these
troglodytes have, doesn’t that destroy the whole basis upon which the
commercial is based? If they wanted to show how easy their website is, they
should show Rosie O’Donnell signing up for coverage.

And this is just too good to check, from a reader:

The Carpenters song “We’ve only just begun”, was originally a commercial for a bank. I think it was Bank of America.