5. Comedy - Monkey Business (1952)
Also starring Cary Grant, this movie depicts life as a scientist in the 1950s where animal testing ran free and human testing wasnt all that controversial. Playing chemist Barnaby Fulton, Grant unknowingly allows a monkey to concoct a youth serum that gets mixed into the laboratorys drinking water supply. Once ingested, time goes backwards as we watch the aging Barnaby transform into a youthful punk who flirts with the secretary (a very beautiful Marilyn Monroe), buys expensive sports cars, and changes his hair to suit any teenagers lifestyle. When his wife, portrayed by famed dancer Ginger Rodgers, starts feeling the effects of the same youth serum after ingesting the water during a visit, things start getting crazy. This movie has always made me laugh simply because it is absolutely ridiculous. The idea of a scientist creating something in a lab and it getting out isnt an unpopular subject, but most are the basis for horror and sci-fi films. Grants undying charm and good looks are ever supportive of the illusion that Barnaby is going from an aging scientist to a spritely adolescent and Ginger Rodgers makes a very impressive transition as well, going as far as to change her voice between loving wife and annoying little girl. Marilyn Monroes brief appearance in the film is usually what gets people watching, but once they are in, theyll find it hard to not laugh throughout.