The Litigation Daily covered lots of rulings by lots of judges in 2012, and sometimes they can all blur together. But a few judges stand out, some because of the force of their personalities and convictions, and some because of the significance of their rulings.

We look back at four that made an impression on us in the past year.

Richard Posner

Richard Posner of the U.S. Court of Appeals for the Seventh Circuit certainly had an eventful year. The fearless and fiercely independent judge spent several months feuding with U.S. Supreme Court Justice Antonin Scalia: In one case he tussled over the definition of legislative history; in another he sparred over whether the justice crossed a line when he angrily dissented in last June’s high court decision striking down part of Arizona’s immigration statute.

In a ruling in November, Posner appeared to defy Scalia again when he reversed the denial of class certification in a case in which Whirlpool Corporation faces claims that its high-efficiency washing machines are prone to developing smelly mold. In a bracingly uncomplicated eight-page opinion, Posner emphasized the importance of promoting efficiency in class action litigation. That could set up another confrontation with Scalia, who wrote the opinion in the landmark Wal-Mart v. Dukes decision, which could be read to reject such concerns about efficiency in mass litigation.

In the realm of intellectual property, Posner in June tossed Apple Inc.’s patent infringement lawsuit against Motorola Mobility after finding that neither side could prove damages. The judge also published an article in The Atlantic in July arguing that there are too many patents in America and they lead to excessive litigation.

Lucy Koh

In contrast to Posner, who has been on the bench since 1981, Lucy Koh is just starting her judicial career. Koh, who was appointed to the U.S. District Court in San Jose in 2010, loomed just as large as the trailblazing judge handled several crucial technology disputes. She presided over the August trial in which Apple won a record $1 billion verdict against Samsung for infringing patents used for smartphones and electronic tablets. Last week Koh denied Apple’s bid for permanent injunctions against 26 Samsung products. In doing so she set a higher bar for patent holders seeking injunctive relief, by making them demonstrate that they lost market share as the result of a specific infringing aspect of a competitor’s product.

In other tech cases, Koh presided over Fujitsu’s unsuccessful patent infringement suit against Belkin Inc., D-Link Corp., and NetGear Inc. that was decided this month. And in April, she allowed a novel antitrust class action to proceed that accuses Apple, Google, and five other big tech companies of conspiring to suppress employees’ salaries.

Jed Rakoff

U.S. District Judge Jed Rakoff of Manhattan is no stranger to these pages. After boldly scuttling the proposed $285 million settlement between Citigroup and the Securities and Exchange Commission in 2011, Rakoff is now on the defensive. The SEC and Citi have appealed Rakoff’s ruling and the U.S. Court of Appeals for the Second Circuit has taken the rare step of hiring an attorney to defend Rakoff’s actions. John Wing of Lankler, Siffert & Wohl, who has been appointed pro bono counsel to Rakoff, has charged in appellate briefs that the SEC and Citi have misrepresented Rakoff’s ruling to the court and twisted his words. Oral arguments are scheduled for February.

Rakoff also presided over the megawatt trial of former Goldman Sachs Group Inc. director Rajat Gupta, who was convicted of feeding inside information to Galleon Group hedge fund founder Raj Rajaratnam. Rakoff sentenced Gupta to two years in prison, rejecting a much longer stint the government sought under sentencing guidelines because those rules focused on the amount of money involved in Rajaratnam’s trades.