The Firm: This highly regarded New York group focuses on representing Fortune 500 companies in significant M&A deals, while also offering nontransactional advice to boards, compensation committees and individual executives. In recent highlights, the group advised the compensation committee of Yahoo! on the high-profile hiring of Marissa Mayer from Google.

Sources Say: "A very deep firm."

Key Individuals: Michael Sirkin is "a true benefits man," who focuses on nonqualified arrangements relating to executive compensation as well as stock option plan design. He recently advised the management of Neuberger Berman as it sought to spin the group off from Lehman Brothers. One peer commented: "If I were a CEO, I'd want him on my side."

Based in DC, Paul Hamburger co-heads the firm's employee benefits, executive compensation and ERISA practice. Described as "very skilled" by peers for his expertise in ERISA law, he advises clients on a range of benefits issues, with a focus on tax-qualified retirement plans.