From the 1970s...
Farrah Fawcett for Faberge:

Andy Warhol for Pioneer:

Paul Newman for Coca-Cola:

From the 1980s...
Phil Collins for Beyerdynamic:

Sophia Loren for Blackgama:

Bill Gates for the Wall Street Journal:

Wllie Nelson for Wrangler:

Cybill Shepherd for L'Oreal:

Found at Vintage Ad Browser.