A site has posted 25 years of Taco Bell TV commercials HERE. I particularly enjoyed the one from 1979 characterizing Taco Bell as "The Fresh Food Place," which ends with a teaser for the 11 PM local news from the time. ("Is gasoline rationing imminent? Details at 11.")
Also notable, I thought, was one from from 1989 in which a series of young men in a Taco Bell seem to be staring, mouths agape, at Patrick Swayze's jeans rather than the bag of food he's carrying.