Dumb and Dumber (1994)
Imbecilic best friends Lloyd Christmas (Jim Carrey) and Harry Dunne (Jeff Daniels) stumble across a suitcase full of money left behind in Harry's car by Mary Swanson (Lauren Holly), who was on her way to the airport. The pair decide to go to Aspen, Colo., to return the money, unaware that it is connected to a kidnapping. As Harry and Lloyd -- who has fallen in love with Mary -- are pursued across the country by hired killers and police, they find both their friendship and their brains tested.
Dumb and Dumberer: When Harry Met Lloyd (2003)
After years of homeschooling, dim-bulb teen Harry Dunne (Derek Richardson) finally makes the leap to public school and meets the equally intellectually challenged Lloyd Christmas (Eric Christian Olsen). The duo land in a "special needs" class created by Principal Collins (Eugene Levy) in order to bilk money from parents to fund his condo in Waikiki, Hawaii. His corruption is discovered by Jessica (Rachel Nichols), a fellow student who asks Harry and Lloyd to help her prove Collins' guilt.