Ping Zing irons (1992)
It's impossible to replace a legend like the Ping Eye2 irons, but the buzz surrounding the Ping Zing iron was so great that it was the talk of the 1992 PGA Merchandise Show despite never being seen. In fact, the unusually shaped, oversized club with a dramatic improvement in moment of inertia over its predecessor didn't even make its way on to the PGA Tour until two months later, and wasn't in stores for another month after that. More than 5,000 orders were taken before the company's sales staff had even seen the club. Alas, less than two years later, the odd shape was being tweaked in a Zing2, and Ping, which had been the No. 1-selling iron for 12 straight years, was no longer at the top.