Nothing (other than sex and violence) sells technology like celebrities. This top 5 worst list includes products that are just terrible (Shaq Fu), commercials that are plainly awful (Microsoft), and advertisements that are nonsensical:

1 - Microsoft -
Microsoft and Jerry Seinfeld? This was a partnership that made even less sense than the horrible two ads that ensued. The ads were unfunny and boring, so they were quickly pulled from the air, but not before costing Microsoft a reported $10 million in fees to Seinfeld. By the way, Jerry had a Macintosh during his ’90s show:

2 - AT&T -
Instead of spending every dime that it can allot into fixing its network woes, AT&T recently hired Luke Wilson (whom I have always liked more than his brother) to defend itself against Verizon’s wave of attacks. Via prime time television advertisements, Wilson shows that AT&T’s has 97% coverage of all Americans, even though the dissatisfaction with the company is due to limited 3G coverage:

3 - Electronic Arts -
What could possibly go wrong when Shaq, video gaming, and kung-fu are mashed together? Back in 1994, Electronic Arts published what is now considered to be one of the worst video games in history. The television spot was bad, but the game play and concept were even worse:

4 - Comcast -
A weird combination of Shaquille O’Neal and Ben Stein selling something that they probably know little about. I personally find these ads annoying and devoid of humor:

5 - eHarmony -
Okay, so this is a spoof, but imagine if it were real. Tiger Woods and eHarmony!