The Firm: Proskauer's robust M&A team operates out of its New York, Los Angeles and Washington, DC offices. The group has carved out an excellent position in the national landscape, attracting a number of multibillion-dollar mandates from notable names such as Ares Management, Neuberger Berman and Arkema. This past year has seen lawyers engaged on the $2.95 billion merger of two major REITs, representing American Realty Capital Trust across the table from Realty Income Trust.

Sources Say: "Excellent interface, superb mastery of the other party's requirements and excellent integration of the many skills that are required in an M&A deal."

Key Individuals: Michael Woronoff heads the firm's Los Angeles office and co-heads the global M&A group with New York-based Ron Papa.