Love them or hate them (or, more likely, fear them) you can’t ignore Gibson, Dunn & Crutcher’s cascade of litigation triumphs. The firm may not have taken top honors again—it’s been the defending Litigation Department of the Year champion since 2010—but Gibson Dunn’s litigators are still cooking with gas.

Gibson Dunn won seemingly unwinnable defense verdicts and secured massive settlements during our contest time frame. It helped achieve a historic win in Hollingsworth v. Perry, the U.S. Supreme Court case that effectively legalized gay marriage in California. The firm also continued turning the tables on plaintiffs and their lawyers, and it cemented its reputation for helping whole industries strike down controversial government regulations. Gibson Dunn’s deep roster of appellate advocates, meanwhile, kept shaping the future of class action litigation. Class actions may never disappear. But thanks to Gibson Dunn (and with apologies to Grover Norquist), they may someday be small enough to drown in the bathtub.

LITIGATION HIGHLIGHTS: Gibson Dunn doesn’t just successfully defend class actions, it chips away at the body of law that supports them. Building on the firm’s 2011 success in Wal-Mart Stores Inc. v. Dukes, partner Miguel Estrada’s March 2013 Supreme Court victory in Comcast Corp. v. Behrend erected additional barriers for plaintiffs seeking class certification. That same month, partner Theodore Boutrous Jr. convinced all nine justices to crack down on a procedural tactic that kept cases in plaintiffs-friendly state courts.

Theodore Olson still anchors Gibson Dunn’s appellate practice, and it’s easy to see why. In a long-running battle over Argentine bonds, Olson won a federal appeals court ruling that upended the Republic of Argentina’s plan to repay its many creditors. Siding with Olson’s hedge fund clients, the court upheld a series of injunctions designed to pressure Argentina into paying bondholders that have refused to restructure their debt. And Olson shares credit with Boies, Schiller & Flexner’s David Boies for Hollingsworth, which left in place a lower court decision striking down the California ballot initiative that banned gay marriage in the state.

Gibson Dunn also showed off its knack for turning its clients’ accusers into the accused. Take Paul Ceglia, the man who claimed to hold a decade-old contract with Facebook Inc. founder Mark Zuckerberg that entitled him to half of the social networking company. Partner Orin Snyder not only persuaded a magistrate judge that Ceglia’s purported contract was fake, but evidence amassed by the firm helped get Ceglia indicted. (Ceglia moved to dismiss the charges in November arguing that “the government has dressed up a civil claim for malicious prosecution as a criminal fraud prosecution.”) Gibson Dunn’s Randy Mastro, meanwhile, all but convinced a judge in New York that a multibillion-dollar Ecuadorian environmental judgment against Chevron was a wholesale fraud. (A decision was pending at press time.)

In other high-stakes matters, clients have learned to trust Gibson Dunn to undermine the credibility of their opponents. That’s what Snyder did in a multibillion-dollar breach of contract case Cablevision Inc. brought against DISH Network Corp. Early in the case, Snyder convinced a New York state court judge that DISH employees destroyed evidence prior to the litigation. When the case went to trial in September 2012, Snyder dropped the bombshell accusation that Dish’s cover-up had been even larger than initially suspected. Dish settled the case on terms favorable to Cablevision that included a $700 million up-front cash payment. “Orin and his team just kept digging and digging, instead of closing out an issue and moving,” said Cablevision executive vice president and general counsel David Ellen.

Another Gibson Dunn client, Hewlett-Packard Company, turned to partners Jeffrey Thomas and Samuel Liversidge in a contract case against Oracle Corp. related to software for certain HP server products. Along with cocounsel at other firms, the pair prevailed for HP in an August 2012 bench trial, paving the way for a potential damages award in the billions of dollars.

For Artemis SA, partner Robert Weigel persuaded a Los Angeles jury to reject claims by former California Insurance Commissioner John Garamendi in a dispute over a bond transaction. The sought-after $4.3 billion judgment would have gone into California’s coffers, and Artemis, which is controlled by French billionaire Francois Pinault, wasn’t the most sympathetic defendant. But the jury determined that Artemis shouldn’t pay a cent of the state’s alleged damages.

BIGGEST LOSS: Gibson Dunn’s most high-profile loss came in Apple Inc.’s closely watched battle with the U.S. Department of Justice over e-book pricing. But the firm has also faced setbacks in its defense of the for-profit education company ITT Educational Services Inc., which is fighting whistleblower claims that it defrauded the federal government. With its signature aggression, Gibson Dunn won a ruling that put the plaintiffs lawyers driving the case on the hook for $400,000 in sanctions. But an appeals court vacated the sanctions award and revived the case in July 2013, finding that the plaintiffs lawyers acted properly.

CLIENT FEEDBACK: “Orin and his team are genuinely the full package,” says Ellen. “They do all the conventional parts of complex litigation exceptionally well. But their constant focus on outside-the-box analysis and strategies sets them apart from most other firm.” On the Docket: A team of Gibson Dunn patent litigators led by Joshua Krev­itt will have a turn in the spotlight in March 2014, when they’ll represent Apple in another patent infringement trial against rival Samsung Electronics Co. Trial is also approaching in a lawsuit challenging California’s teacher tenure rules, which the firm argues are making it nearly impossible to reform struggling schools.

Department Size and Revenue

Partners: 177 Associates: 465 Other: 19

Department as Percent of Firm: 60%

Percent of Firm Revenue 2012: 59%