Topping the list is:
"$160 million – McReynolds, et al. v. Merrill Lynch & Co.
The largest settlement of 2013 has its roots eight years earlier, when in 2005, broker George McReynolds accused Merrill Lynch & Co. of giving white brokers more lucrative accounts while denying black employees equal pay and career advancement opportunities. McReynolds filed a lawsuit on behalf of 700 black brokers who worked for Merrill. Before the suit was settled out of court in August, it had seen two appeals in the Supreme Court and survived Merrill Lynch's acquisition by Bank of America in 2009." (link)
It is also gratifying to see a case I worked on for several years with my prior firm at #8.
"$3.1 million – Easterling, et al. v. State Of Connecticut, Department Of Correction
Similar to the Chicago case, this suit alleged that the a physical fitness test composed of a 1.5 mile run required by the Connecticut Department of Corrections was not a business need, and that it discriminated against female candidates. As a result over 200 women who applied for a Correction Officer position in 2004 o4 2006, were certified for the class. The settlement was finalized in July." (link)
(*small correction to IC - the Easterling class totaled 124 class members not 200)