Insurance companies are a key component of the Berkshire Hathaway empire, and if nothing else, Warren Buffett can take credit for making carriers an appealing class of stock to own, as people look to imitate his magic.

Year-end underwriting profit from Berkshire Hathaway's primary insurance operations totaled $248 million in 2011.

Legend has it that Buffett's interest in insurance began during the 1950s. One fateful day, Buffett, then a young man in his 20s, struck up a friendship with Benjamin Graham, a prominent shareholder and future chairman of GEICO, during the course of a lengthy discussion on insurance.

Berkshire Hathaway acquired GEICO, the third-largest private-passenger auto insurer in the United States, and its subsidiaries in 1996.

The acquisition of General Re, one of the largest reinsurers in the world based on net written and capital premiums, followed in 1998.

Berkshire Hathaway's other subsidiaries underwriting P&C insurance, or the "Berkshire Hathaway Homestate Companies," lists National Indemnity Co., Medical Protective Co., Applied Underwriters, U.S. Liability Insurance Co., Central States Indemnity Co., and Kansas Bankers Surety, among others.

"If the insurance industry should experience a $250 billion loss from some mega-catastrophe—a loss about triple anything it has ever faced—Berkshire as a whole would likely record a moderate profit for the year because of its many streams of earnings," read a 2011 statement from the company. "Concurrently, all other major insurers and reinsurers would be far in the red, and some would face insolvency."

—Anya Khalamayzer

#24 J. Robert Hunter: Gadfly-in-Chief

J. Robert Hunter doesn't shy away from a fight. After serving both the private sector and the federal government, he now raises many issues—and eyebrows—as a consumer advocate as director of insurance for the Consumer Federation of America.

Former U.S. Rep. Earl Pomeroy (D-N.D.) calls Hunter a "provocateur extraordinaire," and this portrayal can be credited to Hunter's willingness to raise tough questions to a tough crowd.

"Sometimes I'm in a big meeting with insurance executives, and they all groan…but I learned to think of that as applause," Hunter tells PC360. "I ask a tough question they don't like, so they must be afraid of it."

The industry has denied most of his criticisms. The Insurance Information Institute and its president, Robert Hartwig, have disputed the methods Hunter and the Consumer Federation of America used to gather data in one report and have accused another report of "manufacturing a phantom problem." The Heartland Institute has even declared one report as "dead wrong."

Hunter has held various positions in the industry, helping to lend some credence to his claims. Spanning 50 years, he has served Atlantic Mutual, Centennial, ISO and AIPSO. He has worked in regulation in the Federal Insurance Administration under Presidents Gerald Ford and Jimmy Carter. As part of these positions, he oversaw the National Flood Insurance Program. In 1993 he was named Texas Commissioner of Insurance.

His awareness of consumer issues occurred while serving as chief actuary for the Federal Insurance Administration in 1971. Depositing his first paycheck, he realized he was paid by American citizens and resolved to think about regulation from the citizens' point of view. His resolve was strengthened after becoming a Christian in 1978.

"I thought about how the poor are impacted by a lot of things like not being able to afford auto insurance and how they are gypped on claims," says Hunter. "I thought God had prepared me with my actuarial experience for what he was calling me into."

Together with Ralph Nader, in the 1980s he formed the National Insurance Consumer Organization, where he served as president.

Hunter has chastised insurers and regulators on NFIP ("the rates are not adequate to cover the risks"); medical malpractice ("there is an explosion in premiums charged by mismanaged insurers"); transparency ("they try very hard to keep people confused"); and forced place insurance ("insurance companies and banks are in a deal"), among many other issues.

—Melissa Hillebrand