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Sinead O'Connor vs. Miley Cyrus
Nothing compares 2 this budding rivalry. Funny enough, it all began with a compliment: Cyrus acknowledged that some of her recent creative/aesthetic decisions, including her ''Wrecking Ball'' video, were inspired by O'Connor's ''Nothing Compares 2 U.'' But O'Connor strongly objected to the association and lectured Miley in a lengthy open letter. Cyrus responded more succinctly, and a little immaturely, via Twitter, evoking O'Connor's troubled history. This set things off, prompting O'Connor to pen not one but two more letters — so far.
Winner: The Postal Service (not the erstwhile electronic band). Never has letter-writing been so popular! But really, though, it's obviously ongoing.
2 of 15
Charlie Sheen vs. Chuck Lorre
Self-proclaimed ''Warlock'' Sheen's hard-partying ways were always well known, but things exploded in February 2011. The star went on a series of radio rants against Two and a Half Men creator Lorre, calling him a ''clown'' and proclaiming, ''I'm so tired of pretending like my life isn't perfect and bitchin' and just winning every second.'' Lorre, in turn, scattered references to the imbroglio in his trademark title cards at the end of each episode. Men eventually shut down production for a while as its ''winning'' star hit the media circuit and launched a bizarre comedy tour. Sheen was ultimately replaced by Ashton Kutcher, but he almost immediately booked a new gig starring on FX's Anger Management.
Winner: Toss-Up. Lorre produces several of TV's most successful shows, including Men. Sheen has job security at Anger Management for the foreseeable future. Both ''winning,'' both losing face in the process.
3 of 15
Elton John vs. Madonna
This decade-long diva battle began way back in 2002 when Sir Elton declared that Madonna's ''Die Another Day'' was ''the worst Bond tune ever.'' He continued to pile on, accusing her of lip-syncing multiple times and calling her a ''fairground stripper'' at one point. John's husband David Furnish even got in on the action, saying, ''I like Madonna's music but not her movies. She should stick to what she's good at.''
Winner: Madonna. That Furnish quote came during the 2012 Golden Globe Awards, where Madonna's ''Masterpiece'' beat out John's ''Hello Hello'' for Best Original Song. And John recently revealed that the decidedly one-sided conflict ended in France in the summer of 2012. ''I apologized profusely,'' John said. ''She was very gracious, she accepted our apology, and then we bought her dinner.''
4 of 15
Jay Leno vs. Conan O'Brien
Make that ''Jay Leno vs. The Rest of Comedy.'' The shortish version: In 2009, O'Brien officially took over as host of The Tonight Show while Leno moved from Tonight to a new nightly show in the 10 p.m. timeslot. In January 2010, NBC decided to push Leno's start time to 11:35 p.m. and Tonight's start time to 12:05 a.m. — effectively relegating the ex-Late Night host to be Leno's second fiddle once more. The problem: O'Brien refused to move. Thus began a tense negotiation period filled with cheers for ''Team Coco'' and scores of uncomfortable monologue jokes. Two weeks later, O'Brien left the network for good, eventually moving to TBS...and Leno returned to his old roost, tarnished legacy and all.
Winner: Conan O'Brien. Conan isn't as widely watched as his NBC talk shows were — but many viewers will never see Leno the same way again. Oh, and did we mention that Jay's being pushed out for a second time next winter — and replaced by Jimmy Fallon, Conan's Late Night successor?
5 of 15
Eminem vs. Mariah Carey
Em and Mimi's cold war began after they supposedly dated in 2001 up through 2009, when the two traded the diss songs ''Obsessed'' (hers) and ''The Warning'' (his). Marshall insisted the two were an item and spewed nasty insults in songs. Mariah denied they were ever even romantic.
Winner: Mariah Carey. If only for her creative responses, including parodies of the Detroit rapper on stage and in the ''Obsessed'' video, where she actually dressed in drag as a stalker Eminem.
6 of 15
Tom Cruise vs. Brooke Shields
Blame L. Ron Hubbard. The Scientology founder frowned upon psychiatry; so do his followers, including outspoken Scientologist Cruise. In the spring of 2005, Shields detailed her battle with postpartum depression — and her use of the antidepressant Paxil — in a memoir. Soon after its publication, the actor criticized Shields on Access Hollywood, calling her ''irresponsible'' for advocating antidepressant use. Shields shot back with a strongly worded statement (''Tom should stick to saving the world from aliens and let women who are experiencing postpartum depression decide what treatment options are best for them'') and an incisive New York Times column.
Winner: Brooke Shields. Thankfully, there's a happy ending — one year later, Shields told Jay Leno that Cruise had privately apologized to her. See, '80s icons can just get along!
7 of 15
Axl Rose vs. Kurt Cobain
Axl and Kurt were natural enemies in 1992: One was a loose cannon who saw his relevance ebbing; the other resented the macho types who dominated the culture. Backstage at the MTV Video Awards that year, according to the book Heavier Than Heaven, Cobain's wife Courtney Love sassed Axl, sarcastically offering to make him the godfather of her and Cobain's daughter Frances Bean. Axl told Kurt to ''shut your bitch up'' — and Kurt mockingly repeated the order to his wife. The two rock stars never connected before Cobain's death, but Kurt had already proven how ridiculous — and predictable — the whole conflict was, and refused to let it escalate.
Winner: Kurt Cobain. Legacies notwithstanding, the grunge god could never have mangled Axl's face as much as Rose himself did.
8 of 15
Murphy Brown vs. Dan Quayle
During the 1992 presidential election, the incumbent Republican Vice President decried the country's shredded moral fabric by name-checking Candice Bergen's eponymous single-mom TV anchor. Most notably, Quayle accused Brown of representing the downfall of society's family values by ''mocking the importance of a father, by bearing a child alone, and calling it just another 'lifestyle choice.''' Creator Diane English shot back that Quayle's diatribe was ''irresponsible'' and challenged him to a public debate. Absent a response, she penned a season 5 opener in which her heroine addressed the soon-to-be ex-VP head-on. It was called ''You Say Potatoe, I Say Potato'' — a dig at a blunder Quayle made during an elementary school spelling bee just weeks after his Brown bash.
Winner: Murphy Brown. Quayle lost the election that fall, making him a one-and-done veep. Murphy stayed on the air for another six years.
9 of 15
Drake vs. Chris Brown
These two titans of smooth hip-hop and R&B were destined to collide even if Drake hadn't had a rumored relationship with Brown's ex-girlfriend Rihanna. It came to a head in June 2012, when a dust-up between their respective crews in a Manhattan nightclub led to broken glass and bloody lacerations for several members of the entourages.
Winner: Drake. Success is the best revenge: Drake's Nothing Was the Same moved 658,000 copies in its opening week, while Brown's last album Fortune only did 135,000. The hatchet may have been buried though — Brown recently posted video of he and Drake in the studio.
10 of 15
Alec Baldwin vs. Pretty Much Anyone
Who hasn't Baldwin battled with? He had a wildly contentious divorce from ex-wife Kim Basinger, called his own daughter a ''little pig,'' has been engaged in street brawls with more than one paparazzo, got sold out by former almost-Broadway costar Shia LaBeouf, and even unleashed his wrath on a flight attendant who wouldn't let him play Words With Friends during takeoff. If you're on Twitter, even you've probably felt the burn of Baldwin's searing 140-character tantrums.
Winner: Definitely not Alec Baldwin...and yet, also, kinda Alec Baldwin. The guy has spent the better part of the past 15 years as the poster boy for anger mismanagement, and yet he has the respect of his peers in entertainment and politics — signaled by armfuls of awards and an upcoming MSNBC show.
11 of 15
Kanye West vs. Taylor Swift and Kanye West vs. Jimmy Kimmel
Never one to keep his opinions to himself, West walked on stage at the 2009 MTV Video Music Awards to announce to the world that Beyoncé should have won the Best Female Video prize that Swift was accepting. That began the era of Yeezy as Public Enemy Number One, though his self-flagellating apology tour and exile thereafter led to perhaps his best album to date, My Beautiful Dark Twisted Fantasy. More recently, West took it personally when late night host Jimmy Kimmel poked fun at some quotes he gave during a rare TV interview, and responded with a series of all-caps tweets — which Kimmel also mocked on the air.
Winner: Not Kanye. Yeezy will never end up on the winning side of a feud. What would he rap about otherwise?
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T.R. Knight vs. Isiah Washington
In response to rumors that Washington had used a gay slur in reference to his Grey's Anatomy costar Knight during the show's third season, Washington decided to clear the air by telling reporters backstage at the 2007 Golden Globes that in fact, ''No, I did not call T.R. a f----t.'' In addition to looking like a homophobic bully (Knight said the ordeal was what prompted him to come out), Washington spent much of the next year trying to rehabilitate his image through apologizing and doing doing PSAs.
Winner: T.R. Knight. Five months after the incident, Washington lost his job on the show and, other than a spot on the ill-fated Bionic Woman reboot, hasn't been heard from much since.
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One Direction vs. The Wanted
Like the Backstreet Boys and *NSYNC a generation before, The Wanted and One Direction engaged in a passive-aggressive war of words in the early part of 2013. In a fitting turn for the parties involved, it was pretty mild: After hearing his group had been called out at a 1D show, The Wanted's Tom Parker tweeted at Louis Tomlinson, ''You even talk about us at your own gigs. Are you that upset you didn't get in this band?'' Tomlinson shot back with a tweet of his own: ''Pal, we both know I wouldn't waste my time auditioning for your band. You humour me with your bad boy persona.'' And let us not forget the time 1D member Zayn Malik referred to Wanted playboy (and Lindsey Lohan cohort) Max George as ''chlamydia boy.'' Shade!
Winner: Squealing teen girls. According to The Wanted's Nathan Sykes, the beef has been squashed. Considering One Direction had their own concert film drop recently, it's easy to see who the victor is this time around.
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Donald Trump vs. Rosie O'Donnell
O'Donnell, then on The View in 2006, fired the first shot, calling Trump a ''snake-oil salesman'' and maligning his hair, his Miss USA pageant, and his finances. Threatening to sue, Trump called her fat, a slob, and a loser. Neither backed down — though Trump never sued — and in 2012, Trump piped back up to rejoice in O'Donnell's OWN show being cancelled: ''Rosie fails at everything.''
Winner: TBD. Rosie and The Donald are still feuding (not that anyone's paying attention).
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Jay Z vs. Nas
Of music's (and particularly rap's) many feuds, this might be the only one that produced more good than bad. It all started when the two towering figures of NYC's rap renaissance, tired of sharing the throne, duked it out to determine who'd represent the five boroughs. Fortunately for fans, they did it through some great songs: Jay Z took the first shot with a diss on his Blueprint track ''The Takeover''; Nas later fired back with ''Ether.'' Those great songs were followed by some lesser ones, which might've been what prompted them to finally call a truce in the form of ''Black Republican.''
Winner: Tie. They're just two rich friends now.