The biggest business feuds of 2013

Carl Icahn vs. Bill Ackman

In January, Carl Icahn and Bill Ackman went on CNBC supposedly to debate Herbalife (HLF). Instead, Icahn spent half an hour calling Ackman a "crybaby," a "major loser," and either "the most sanctimonious guy I met in my life or just arrogant." Ackman said Icahn was dishonest. Much of the TV smackdown was about a deal the two did together a few years ago that ended up going to court with Ackman winning. But the two continued to fight over Herbalife for the rest of the year. Ackman says the nutritional supplements company is a fraud. Icahn says it has a future, but admits he bought shares in the company in part just to get back at Ackman, which has worked. Herbalife's shares have soared this year, costing Ackman and his investors $500 million.

Bill Ackman vs. Dan Loeb

Icahn wasn't the only one to pile onto Ackman and his losing bet on Herbalife. Shortly after Ackman announced he was shorting the company, another high-profile hedge fund manager, Dan Loeb, bought up shares of Herbalife. He called Ackman's arguments "preposterous." Loeb sold his shares a few months later for a profit, but continued to stick it to Ackman. In July, Loeb posted from his Bloomberg terminal, "New HLF product: The Herbalife Enema, administered by Uncle Carl." Ackman said he was disappointed in his former friend.

Dan Loeb vs. George Clooney and Sony

You don't mess with Hollywood without hearing from the handsomest guy in town. In July, Loeb criticized Sony's management, saying the company's film studio has been turning out flops and should be spun off. Within days, George Clooney jumped to the defense of Sony, which backs Clooney's production company. Clooney called Loeb a "carpetbagger" and "the least qualified person to be making these kind of judgements." He said Sony had had lots of hits this year, and that Loeb was cherry-picking. Loeb responded that he would like to sit down with Clooney and hash things out. No word if the two met.

Sony vs. Microsoft

There were bound to be some elbows thrown between Sony (SNE) and Microsoft (MSFT) in 2013. Both companies were set to release their new video game systems -- PlayStation 4 and Xbox One. But as the consoles neared release, the war of words got more heated than many thought it would. In August, Sony's head of entertainment called Microsoft out for constantly shifting its message on what the new Xbox would be. Microsoft Studio's boss countered that Microsoft was a company that listened to consumers, and that's why changes had been made. Sony countered that Microsoft's retreat was clearly a sign that its strategy for its new console was rebuffed. Who won? There were reports that PlayStation 4 was outselling Xbox, but it's hard to tell. Both systems were two of the hardest to get items for Christmas shoppers. The battle goes on.

Microsoft vs. Apple

In 2013, Microsoft finally retaliated for all those Mac-PC commercials. It began in May with an ad skewering Siri, Apple's (AAPL) digital voice-activated assistant. The ad had Siri continually apologizing for not being able to do what a Windows tablet could do. "I'm sorry, I can only do one thing at a time," Siri says. "Should we just play chopsticks." Apple's iPad mini ads had users playing piano. Then in September, Microsoft released a video of a mock strategy session at Apple. The Apple developers showed up late, because their iWatches had to be sent back to development. Their big idea: "Everyone loves gold, right?" The idea of the ad was that Apple is all style over substance. Microsoft quickly pulled the video from its website, saying it was meant to be lighthearted but was "off-the-mark." Apple countered by selling a record 9 million phones during the first week of the launch of the new iPhone in September.

Apple vs. Dell

Despite all the buzz, Dell has long had the upper hand in the computer market over Apple. The vast majority of the world's computers are PCs running on Windows -- the kind that Dell makes. But in 2013, that seemed to shift. Later in the year, a survey found that, for the first time since the original Macintosh was released, more consumers planned to make their next computer purchase an Apple rather than a Dell.

Dell vs. Carl Icahn

Less than a month after Dell announced plans to go private, Icahn emerged as key opponent. Icahn bought up shares and, in tweets and open letters, said that public shareholders were getting "hosed." Icahn said the computer maker's board should be fired and Michael Dell replaced. Icahn said he would buy out the company himself, and he had lined up another executive to take over from Dell. In the end, Icahn didn't appear to have the financing to get his deal done. Shareholders voted for the Michael Dell-led buyout in October, concluding the most contentious deal of the year. After the deal was done, Dell said the whole saga was bizarre to him. At a companywide meeting after the deal, Dell told employees it was great to still be there and not introducing Carl Icahn. Our advice to Michael: Stay off CNBC for a while.