Best in Show is a comedic film done in the style of a documentary. The actors all speak to the camera directly, in character. The film is about a diverse bunch of people who are all bringing their dogs to participate in a prestigious dog show. There are the Flecks, a married couple who are avid fans of their terriers. Mrs. Fleck appears to have had a wild past. She routinely runs into old boyfriends of hers, much to the discomfort of Mr. Fleck. There is a wealthy trophy wife who is showing her prized poodle. Her husband is very old and confined to a wheelchair so she is accompanied by her dog's trainer. The dog's trainer seems to have romantic intentions towards the trophy wife as well. Meg and Hamilton Swan are another married couple who are obsessed with Starbucks, Ikea, and babying their dog. Harlan Pepper is a good old country boy who is showing his bloodhound. Scott and Stefan are a couple that treat their dogs like they are children.
Everybody comes to Philadelphia to compete in the dog show and tensions are high. The Flecks have no money and are forced to sleep in a hotel's supply closet. The Swans have forget their dog's toy at home and are desperate to find a replace somewhere in the city. They are unable to and they begin to fight with each other. When it's time for the dog show, many of the dogs do not cooperate. One of the them even pees on a judge. Meanwhile, Sherri Ann, the wealthy trophy wife, is seemingly living a blissful existence while all the chaos goes around her. The show ends with the Flecks winning, meaning they know have enough money to get back home.