I remember seeing this movie about ten years ago. A group of men rob a gas station, I think, and one man falls in love with a customer they're now holding hostage. At the end of the movie I think they get together, but the man gets arrested.

I could be way wrong but your description sounds a lot like The Chase
Twenty-eight year-old Jackson "Jack" Davis Hammond (Charlie Sheen) is sentenced to twenty-five years in prison for an armed robbery he didn't commit, but manages to escape. To get away from the police while at a convenience store, he takes a hostage, California heiress Natalie Voss (Kristy Swanson), the only daughter of multi-millionaire Dalton Voss (Ray Wise). Threatening Natalie with a candy bar, posing for a gun, Jack disarms a pair of unseasoned, intervening officers. Jack takes their guns then drives off in Natalie's BMW. The chase quickly becomes broadcast live on every TV channel, with scenes filming news coverage from helicopters, the backseat of a police car, and the pavement of the highway. Natalie eventually gets to know Jack during the chase, and later sympathizes with the "gun-wielding, cop-shooting, maniac kidnapper" by comparing her life to his and realizes their similarities despite having different backgrounds. She falls in love with him and begins to believe in him. Later they start kissing and end up having sex while Jack is driving. Jack plans on escaping into Mexico and Natalie proposes a future together.
When the cops block off the border crossing to Mexico, Jack stops before reaching the border, and releases Natalie. She reluctantly leaves and in the final confrontation with the police, Jack appears to be defiant and goes down in a blaze of glory. Moments later, however, this is revealed to be a mental projection of what would happen if he doesn't surrender. Jack surrenders but Natalie takes a television producer hostage with the gun given to her by Jack before she was surrendered to the police. Natalie blows up a nearby police helicopter, hijacks a news helicopter and escapes with Jack across the border into Mexico. The next scene reveals that after some time has passed, the pair are relaxing in freedom on a beach

Yeah I've heard of the movie you're talking about but that's not the one. Sounds like a good movie though..