Jesse James and Sandra Bullock Jesse James and Sandra Bullock

2010 may just go down as the  year of shocking celebrity breakups. First, there was Sandra Bullock's divorce from Jesse James. Then Courteney Cox and David Arquette announced their separation. And now, Scarlett Johansson and Ryan Reynolds have called it quits.

Look back at our list of some of the most surprising splits of the year, and tell us which breakup floored you the most.

New Oscar winner Sandra Bullock filed for divorce from Jesse James shortly after several women — namely tattoo model Michelle "Bombshell" McGee — claimed to have had affairs with the Monster Garage star. Bullock and James had been married since 2005.

Melissa and Tammy Etheridge separated after nearly nine years of marriage. The two had a commitment ceremony in September 2003. Tammy gave birth to twins, daughter Johnnie Rose and son Miller, three years later.

Jenny McCarthy and longtime boyfriend Jim Carrey called it quits after five years together.

Joe Jonas and Demi Lovato split after a few months of dating. "Things didn't work out but we'll remain friends," Lovato tweeted.

Halle Berry and model Gabriel Aubry ended things after four years. "She is, and will forever be one of the most special and beautiful people that I have ever known, and I am certain that we will continue to have only love and respect for one another," Aubry said to Access Hollywood . The couple has a daughter named Nahla.

The Bachelor's Jake Pavelka and Vienna Girardi split shortly after his stint on Dancing with the Stars. "Sometimes love just isn't enough in a relationship," Pavelka told TMZ. The couple met and got engaged during The Bachelor's 14th season.

Former Vice President Al Gore and wife Tipper announced their separation two weeks after their 40th wedding anniversary. "This is very much a mutual and mutually supportive decision that we have made together following a process of long and careful consideration," the couple said.

Kelsey Grammer and his wife, Real Housewives of Beverly Hills star Camille Donatacci, filed for a divorce after a 13-year marriage that produced two children — daughter Mason and son Jude. The Frasier star has since gotten engaged to Kayte Walsh.

Millionaire Matchmaker Patti Stanger called off her wedding to Andy Friedman after dating for more than six years. The couple split up because Stanger claims Friedman couldn't commit to having a family. "You have to agree on the non-negotiables," she tweeted.

Rachel Bilson and Hayden Christensen called off their engagement after the two reportedly took a break to re-evaluate their relationship. The pair, who co-starred in the 2008 action movie Jumper, announced their engagement in February 2009.

Bristol Palin and Levi Johnston called off their engagement — for a second time. "He's just obsessed with the limelight and I got played," Palin said.

Mad Men's  Elisabeth Moss filed for divorce from husband Fred Armisen. The Saturday Night Live star proposed to Moss in June 2009 and the couple wed in October.

Billy Ray Cyrus and wife Tish filed for a divorce after 17 years of marriage. The two have five children together, including pop star Miley Cyrus.

Gossip Girl stars Blake Lively and Penn Badgley called it quits. The stars began dating in December 2007, shortly after the CW series premiered.

Christina Aguilera filed for divorce from husband Jordan Bratman, citing irreconcilable differences. The couple, who wed in November 2005, have a son, Max.

Courteney Cox and David Arquette separated after 11 years of marriage, but the Hollywood couple has not filed for a divorce. The pair met on the set of the first Scream film and have one daughter together named Coco Riley.

Eva Longoria filed for a divorce from Tony Parker after three years of marriage. According to a report, the Desperate Housewives star split from the San Antonio Spurs point guard after finding text messages between him and a mutual female friend that date back for a year.

Charlie Sheen filed for divorce from his third wife, Brooke Mueller, days after police were called to the Two and a Half Men star's New York City hotel room, which was severely damaged. The two married in May 2008 and have twin sons.

Scarlett Johansson and Ryan Reynolds announced an "amicable" end to their marriage. The Hollywood It Couple began dating in 2007 and wed later that year in a private ceremony. "We entered our relationship with love and it's with love and kindness we leave it," the two said in a statement.

Michael C. Hall and Jennifer Carpenter recently revealed that they had been "separated for some time" and filed for a divorce. The Dexter stars — who play foster siblings on the Showtime drama — met on the set and married Dec. 31, 2008.