Couples didn’t get any hotter in the early 2000s than Jennifer Lopez and P. Diddy (aka Puff Daddy at the time). The two began dating in September 1999 around the time of the release of Lopez’s breakthrough album On The 6. The two would later split in February 2001 following Diddy’s infidelity.

Jake Gyllenhaal and Kirsten Dunst were totally 2000s cool when they began dating in 2002. The couple hit it off after being introduced by Jake's sister, Maggie, who had starred alongside Dunst in Mona Lisa Smile. Their relationship was a super hot one; According to Dunst, the couple liked to keep things hot up by getting it on outside the bedroom. "We tried to spice things up. We had sex in cars, in the bathroom, and even by the sea. The only place we didn't have the guts to try was in a walkway in a hotel because we thought we might get kicked out if we were caught,” Dunst told InStyle. Sadly, the couple split in 2002 because they had different lifestyles. “He’s a stay-at-home boy and I’m an out-on-the-town girl,” Dunst said.

The 2000s also had its share of odd couples that somehow made sense, like the passionate if ultimately short-lived romance between Alanis Morrisette and Ryan Reynolds. These Canadian lovebirds first began dating after reportedly meeting at Drew Barrymore’s birthday party in 2002. Two years later, they announced their engagement. They called it quits in February 2007 after three years of engagement.

Adam Brody and Rachel Bilson (aka Seth Cohen and Summer Roberts on The OC) where everyone's fave on-screen couple that made fans' dreams come true by getting together IRL. The two met on set and began dating in 2003. While they kept things pretty low profile, Bilson did gush about her relationship with Brody to People in April 2006, saying, “We always have a lot to talk about, and we tell each other everything. I feel like I have everything now – the dog, the house, the job, and him. I can’t ask for anything more!” It came as a pretty big shock when they split late that same year.

Another couple that jumped off the screens and into the hearts of fans everywhere in the early 2000s was The Notebook lovers Ryan Gosling and Rachel McAdams. Surprisingly, their love story didn’t happen on set, as according to the film's director, Nick Cassavetes, they didn’t exactly get along. “They were not getting along one day on set. Really not. And Ryan came to me, and 150 people are standing in this big scene, and he says, ‘Nick come here.’ And he’s doing a scene with Rachel, and he says, ‘Would you take her out of here and bring in another actress to read off camera with me?’ I said, ‘What?’ He says, ‘I can’t. I can’t do it with her. I’m just not getting anything from this,’” Cassavetes told VH1. After the film wrapped, however, the two ended up falling for each other and dating from 2005 to 2007. Ryan told GQ of their breakup: "The only thing I remember is we both went down swingin' and we called it a draw."

The most tragic romance of the 2000s was that of Michelle Williams and Heath Ledger. The two met and fell madly in love on the set of Brokeback Mountain in 2004. They even became pregnant with their daughter Matilda while shooting the film. The couple confirmed their engagement in August 2005 and although there were rumors of a secret marriage at the time, they were never actually wed. The couple split in September 2007, reportedly over Ledger’s drug use. Shortly after, on Jan. 22, 2008, Ledger died of an accidental drug overdose.

Nick Lachey and Jessica Simpson’s love was just too pure for this world, but while it lasted it was an early 2000s dream come true. The two first met in 1998 at the Hollywood Christmas Parade where the both pop stars were both performing, but their romance didn’t take off until they crossed paths again a month later at the Teen People party. Lachey told his mother at the time: “I’ve met the woman I’m going to marry,” Simpson told Vanity Fair. The couple began dating and, in February 2002, Lachey popped the question while on a yacht in Hawaii. They were married in October 2002 and their love story was depicted for three seasons on the hit reality series Newlyweds. They called it quits in November 2005, citing irreconcilable differences.

Britney Spears and Justin Timberlake’s love story was the dream of every 2000s teen girl and it seemed like it could have been lifted from a YA novel. The two first met as kids in 1992 when they were both cast in The Mickey Mouse Club. It was when they met again in 1998, while both doing radio interviews for their respective music careers, that things turned romantic. They were the it-couple for the two years they dated. However, they split in 2002 after Spears’ rumored infidelity. While they might not have lasted, the photos of them in head-to-toe denim will live on forever.

Talk about a golden couple. Jennifer Aniston and Brad Pitt were one of those Hollywood duos who were so hot that looking at them on the red carpet felt like staring into the sun. No wonder they burned brightly and then imploded like the supermassive stars they are. The two began their romance in the most Hollywood fashion ever: by being set up on a date by their agent in 1998. They debuted as a couple in September 1999 on the Emmy Awards red carpet. They were married in Malibu in July 2000 and were the picture of bliss until May 2004 when Pitt and Angelina Jolie met on the set of Mr. & Mrs. Smith and sparks flew. Pitt and Aniston announced they were going their separate ways in January 2005.

Jennifer Lopez was half of not one but two iconic 2000s celebrity duos, the later being forever known as “Bennifer.” Lopez and Ben Affleck first met while the two were shooting their film Gigli. At the time, Lopez was married to dancer Cris Judd, but after nine months of marriage they filed for divorce in June 2002. In November 2002, Lopez and Affleck announced they were engaged. Their relationship was a media sensation; their films Gigli and Jersey Girl, however, were not exactly box office or critical magic. In September 2003, just days before they were set to head down the aisle, the couple called off the wedding and in January 2004 they split.

If these unforgettable early 2000s couples tell us anything, it's that love doesn’t have to be forever to be iconic.