Hilarie Burton's Peyton Sawyer went through the toughest journey of any other character during her six seasons on One Tree Hill. She never really had her parents around, was stuck in a love triangle between two brothers, and then another love triangle with a Scott brother and her best friend, and nearly lost her life on more than on occasion.
Through it all, Peyton never stopped striving for greatness and doing whatever it took to achieve her dreams and live her life the way her biological and adopted mothers never got to. Peyton's greatest love story was established in the pilot episode of the series, but she had a few other sweet romances that would have been almost as satisfying as her happily ever after -- and some that were incredibly incompatible.
Nathan Scott
Nathan Scott and Peyton Sawyer were portrayed to be dating at the beginning of the series, with neither of them showing much interest in the other. It was obvious that Nathan used Peyton for sex, and Peyton clung to Nathan as he was the only person giving her the attention she desired.
As soon as Peyton locked eyes with Lucas and Haley started tutoring Nathan it was clear to the audience that these two were not meant to be, and that their soulmates existed elsewhere in the hallways of Tree Hill High. They did the right thing and split early on, and eventually became in-laws following both of their marriages to other people. It was strange how little their high school relationship was referenced later, but that also showed just how meaningless it was to both of them.
Julian Baker
Julian and Peyton dated off-screen (shown in only flashbacks) after she rejected Lucas's proposal and he went back to Tree Hill. Peyton and Julian allegedly fell in love with one another, though their lack of chemistry during the time-jump made that hard for viewers to believe. It was clear from the start that One Tree Hill's Julian Baker and Peyton.
Peyton and Julian's relationship didn't pan out due to her feelings for Lucas never going away, but that didn't stop him from carrying a torch for her. Despite their rocky past, they were able to transition from former lovers to good friends, and she was the one who played matchmaker for him and his future wife, Brooke.
Pete Wentz
In one of the show's most random storylines, Peyton had a brief affair with Fall Out Boy's Pete Wentz during Season 3 of the show, while she was still a high school student. This was the first time a celebrity played themselves and dated one of the main characters, as Nick Lachey did the same thing in Season 5 of the show.
Pete and Peyton's romance was short-lived, though they actually had a good amount of chemistry. However, he was just a rebound from her recently ended relationship with Jake Jagielski, and he was never going to be a long-term option. It was nice to see Peyton happy and giddy for once though, as she had spent so much of the series so far getting heartbroken by Lucas and Jake.
Anna Taggaro
Peyton Sawyer and Anna Taggaro never dated, but there were sparks between them in Season 2 of the series. After breaking up with Lucas, Anna becomes close with Peyton and later develops a crush on her. The two even share a kiss that Anna's brother, Felix, is not happy about.
Though Peyton's sexuality is never specifically addressed, she takes Felix's cruel label in stride and defends Anna, despite not reciprocating romantic feelings for her at the time. Peyton and Anna remain friends until the latter decides to leave Tree Hill. Their relationship wasn't explored much, but could've been a healthy one for Peyton after her previous heartbreaks.
Jake Jagielski
In another world, Peyton Sawyer and Jake Jagielski were soulmates and stayed together until the end of time. Their love story began in Season 1 after the first go-at the Brooke/Lucas/Peyton love triangle. Peyton grew close to Jake and his daughter Jenny, and spent most of her time with them due to the tension created with Brooke and Lucas.
Jake and Peyton's relationship became mature fast, as they took care of a child together and planned their dreams for the future. The biggest obstacle in their way was the custody battle brought on by Jake's ex, Nicki, forcing Peyton to make the tough decision to let Jake go so he could be with his daughter. Eventually they found their way back to one another, but her love for Lucas got in the way of the two of them making it work long-term, even if Jake truly made her the happiest.
Lucas Scott
In Season 4, Lucas Scott famously said to Peyton Sawyer, "It's you. When all my dreams come true, the one I want next to me...it's you. It's you, Peyton." The moment made fans melt and breathe a sigh of a relief that the on-again-off-again couple had finally confessed their love for one another after seasons of back and forth and failed relationships.
Lucas and Peyton were connected from the pilot episode where she almost ran him over with her car, and couldn't stay away from each other after that. Even through love triangles, marriage proposals, almost-weddings, and several near-death experiences, they remained in love and devoted to one another. After all the tension and drama, it was beautiful and bittersweet to watch as they rode off into the sunset with their baby at the end of Season 6.