Bill Bixby and the Radio Shack Tandy 2000 (1983):
By the time Radio Shack changed from the TRS-80 computer moniker to the less "trashy" Tandy name, it had already given poor Isaac Asimov the boot in favour of TV's Bill Bixby.
Bixby had an oddly schizophrenic public image. On one hand, he was the mild-mannered, compassionate dad from "The Courtship of Eddie's Father". In "The Incredible Hulk", however, he was Dr. Bruce Banner, the man with perhaps the worst anger-management problem ever. This ad seems to be going for an "Eddie's Father" vibe, though who knows what would have happened if the Tandy had thrown up its version of the Blue Screen of Death.