Bonnie's love life was often pushed to the backburner in The Vampire Diaries as the show focused more heavily on other characters. The majority of Bonnie's time in the series consisted of her using her powers to come to her friends' rescue or mourning the loss of another person she cared about.
Bonnie's life was the most traumatic out of the characters, and every time it seemed like she might find happiness, it was ripped away from her. Bonnie had a decent amount of romantic interests throughout the series, but other than one that came out on top, there were very few that had a lasting impact.
Ben
Bonnie asks out Ben, who had recently graduated from her high school, to prove to Caroline that she can make the first move. However, Bonnie was not aware that her crush had recently been turned into a vampire. Everything seemed to be going well during their date, but her powers made Bonnie realize something was off the moment they kissed.
When Ben realizes her suspicions, he grabs her before she can flee the restaurant. Bonnie spends the next episode being held captive by Ben, making him her worst possible suitor.
Kai
Kai was Bonnie's love interest in a very loose sense of the word. He was the major antagonist of The Vampire Diaries Season 8 and put Bonnie through the wringer when they were trapped together in the prison world. He would openly flirt with Bonnie, much to her dismay, and would find himself amused by her.
However, due partially to his difficult upbringing, Kai was a sociopath, and his actions make it clear that he doesn't care what happens to Bonnie. But after Kai merges with his brother he adopts some of his attributes, his newfound comion makes him want to reach out to her and make things right. Fans quickly became fond of the ship and gave them the name "Bonkai."
Luka
In another life, Luka and Bonnie could have worked. Despite being painted as the antagonist, Luka wasn't a bad person. Bonnie and Luka both did things to each other that they shouldn't have, and the only reason Luka was working with Elijah was that he wanted to save his sister.
There were sparks flying between them from the moment they met, and even Jeremy picked up on something between them. Luka's death was disheartening, especially because it could have been avoided.
Jamie
Despite how adorable the two of them were together, it was clear that Jamie and Bonnie were doomed from the start. Since he played such a minor role in the series, it didn't seem like a relationship viewers were meant to get invested in.
But they still had some great moments and it was obvious that Jamie had pure intentions with Bonnie. Their short-lived romance was a nice break from all the drama that Bonnie was dealing with throughout The Vampire Diaries Season 3.
Jeremy
There was a time where it seemed as if Jeremy might be the love of Bonnie's life. It was surprising, given that he cheated on her when his dead girlfriend came back as a ghost, but he ended up becoming the most devoted to Bonnie out of everyone. Jeremy was the only one in their group of friends who always knew when Bonnie was at her limit.
Her friends rarely stopped to consider the physical toll Bonnie's powers took on her, and Jeremy made it his mission to look out for her. Bonnie's selflessness caused her to become reckless, so Jeremy made sure to always keep an eye on her and conduct research on the spells she was performing. Their breakup can only be attributed to Steven R. McQueen's departure from the series.
Damon
Damon and Bonnie never dated, but there were plenty of fans who wanted them to. The two were romantically involved in the books, and there were instances when it seemed as if the show might go there as well. Their friendship came as a surprise to everyone, and their bond became one of the deepest in The Vampire Diaries.
If Nina Dobrev hadn't come back for the series finale, it's likely that their relationship would have headed in a romantic direction. But Damon's love story with Elena was pivotal during the first few seasons, so Damon reuniting with her was satisfying to many viewers.
Enzo
Out of the countless relationships on the series, Bonnie and Enzo are one of the few that almost all viewers can agree on. There was no indication that a "Bonenzo" romance would be a possibility when Enzo first ed the cast, but it ended up being a pleasant surprise. Enzo loved Bonnie selflessly, and he would walk through fire to keep her safe.
Unlike many of her friends, he cared about her emotional wellbeing and he recognized what an incredible woman she was. As Bonnie said herself, all her life she wanted to be loved the way Enzo loved her, making their romance stand apart from the rest. Her reaction to his death was one of the most heartbreaking scenes of the entire show.