The Cable Guy
After Steven (Matthew Broderick) turns down Chip's (Jim Carrey) hand in friendship in favor of working extra hard at maintaining his relationship with Robin (Leslie Mann), Chip proceeds to make his life hell, getting him arrested for the entertainment system he gave him because it was actually stolen. After being arrested, Steven learns from the police that no one named Chip Douglas works for the cable company, and when Chip visits Steven while he is awaiting bail, he says his real name is Larry Tate. After being bailed out, Chip further harasses Steven by having dinner and playing "Porno Password" with Robin and his family, and then gets him fired from his job.
Steven asks his friend Rick (Jack Black) to do a background check on Chip, and Rick finds out Chip had been fired numerous times from cable companies in the last 4 years, all under aliases of different TV characters, and his latest firing was 6 months ago under the alias of Darrin Stephens, the character from Bewitched who had a boss named Larry Tate. Chip Douglas is his current alias. He was fired that time for stalking customers, and no doubt he was fired all those other times for the same reason.
It is revealed that the reason why Chip is so needy of friendship is that his mother was frequently absent from carrying out proper parental duties, always out in bars trying to pick up guys. Chip was left at home by himself a lot with just the TV (the "electronic babysitter"), and it caused him to become literally raised by TV as a result, and TV can't serve the function of being someone to lean on for emotional support and friendship.
Chip eventually abducts Robin and takes her to the town's giant cable dish, where Steven follows and fights him. They fight their way to the tower at the top of the dish, where, as the cops surround the dish, Chip emotionally breaks down from his problems, and goes over the ledge. Steven grabs him by the arm to stop his fall, saying he'll be his friend and that all he needed was help. Chip tells him that even though it is too late for him, "somebody has to kill the babysitter" to save other kids from becoming like him. He falls and lands on the dish's needle, knocking out all TV signals in the city right before the verdict is announced in the Sam Sweet (Ben Stiller) murder trial. Chip survives but suffers a broken back.
As the police take him into a helicopter to the hospital, Chip says goodbye to Steven & Robin. One of the cops calls Chip his buddy and his pal. Chip asks if he is, and the cop says, yeah. Chip's face flashes an evil grin