This movie remains my sister's all-time favorite movies, and I still love it, too. I can't tell you how many times the two of us have watched it. We have it practically memorized. My father loved watching it, too.
Michael J. Fox plays Brantley Foster. He lands a job working in the mail room of his uncle's company, but he really craves executive experience. He takes over the persona of Carlton Whitfield as well as an empty office and starts to rock the boat in the company. He falls in love with the token female executive, Christy, who is having an affair with his uncle. His aunt (by marriage) has developed a big crush on him and literally chases him around the office. Brantley has to balance both of his personalities, which includes many memorable scenes of him changing clothes in the elevator.
The movie is full of all kinds of 1980s cheese and stupid chase scenes, but you can't help but laugh hysterically. It is ridiculous, yet slightly smart at the same time. I cannot help but turn to it every time it is on TV. I highly recommend it for a cheesy laugh and great 80s nostalgia.