There are five cases that every corporate legal counsel has looked at carefully.
The first was the $83 million in retention bonuses paid to PG&E executives while the company was in bankruptcy.
I wrote about this and acted on it turning the PG&E blooper into the modern SEC requirements for executive compensation reporting.
The
second was the HP Board spying debacle. The attorney for the company
never did anything wrong and never made a wrong decision, yet she was
pilloried and executed. (Not in the linked story.)
The third was the recent Supreme Court decision about "obviousness" in patent cases. The Supremes
came down on the side of reasonableness and destroyed years of
disgraceful phony patent filings and tens of thousands of absurd
business stifling patents. 
The
forth was the conviction of Conrad Black and his attorney. The best
stories were in the Wall Street Journal and Business Week but the
outline version is described here. The attorney for Black never gave
illegal advice, it was just a series of advisories that led Black to
misuse the information.
Lastly, this week's conviction of Brocade CEO, Reyes, for backdating stock. I railed
against this outrageous corporate behavior in January and I'm glad to
see that criminal convictions are possible. Will Steve Jobs be next?
Jobs was the most high-profile protagonist in back dating, with Al Gore
providing immediate whitewash.