1. Kool-Aid, Purina Dog Chow, '80s movies, etc. (Kool-Aid Man; Chase the Chuck Wagon; E.T. The Extra-Terrestrial; Raiders of the Lost Ark)
Advertisers don't take long to sniff out fresh blood. Back in 1983, the home console industry was still finding its legs, but the market was already flooded with tacky product tie-in games such as Kool-Aid Man and Chase the Chuck Wagon (hawking Purina Dog Chow). Poorly made movie-licensed titles like E.T. The Extra-Terrestrial and Raiders of the Lost Ark were destined for bargain bins or, in E.T.'s case, landfills. And, with no regulation on who could make a game for what system, third-party developers as out-of-their-element as Quaker Oats rushed to cash in on the new kid-friendly phenomenon.
The result? A devastating industry-wide crash from which it would take several years to recover. Sure, we're not blaming the whole thing on "commercial" games, but they're the most heinous example of the problem: gameplay and innovation had taken a backseat to corporate objectives while designers valued money over creativity. Many had forgotten the most important ingredient in a game was not a particular brand of food or beverage - it was fun.
We learned, we moved on... fittingly, in large thanks to the first console from Nintendo, a company that had a century's worth of experience making games. But you know what they say about the past - forget it and you are doomed to repeat it.