Merger date: 1989
Cost: $4.8 billion

As the eighties came to a close, Japanese tech firm Sony was able to pry Columbia Pictures from the Coca-Cola Company to boost its presence in the movie business. And while Columbia was mired in some sizeable debt at the time, some analysts felt the price tag was fair considering the wide scope and presence of the film studio. But costs of the deal soon skyrocketed as Sony spent $200 million to acquire another production company and a further $500 million to settle a lawsuit with Warner Bros. By 1994, Sony — which had renamed the studio Sony Pictures Entertainment — was forced to take a $3.2 billion writedown on the deal, which perhaps can best be summed up by one word: Blankman. The putrid Damon Wayans comedy released by Sony that same year prompted one critic to simply declare that it "isn't good."

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