Enron

"Credibility," "character," and "leadership" are all important nouns on this pleasant Enron plaque - words that famously describe the culture at Enron as the company repeatedly manipulated earnings and created "special purpose entities" to hide serious liabilities.

Enron's had a market cap of about $90 billion in the year 2000, before it became clear that they were losing money hand over fist. By the end of 2001, it had taken a slight dip to ~$0 - and a few executives would be indicted over the next few years.