There is nothing more timeless than the classic slapstick movies of old. The term "timeless" is used loosely here because modern attempts to emulate this comedy style often turn out pretty flat. For a full day of chuckles and ha-has, check out the following classics, some of which are in the public domain. 

Buster Keaton's "Sherlock Jr." 

The silent comedies from the 1920s are as slapstick as they get. This 1924 film starring Buster Keaton is full of physical gags that make even cartoon makers jealous. Less interesting, though important, is the storyline. Buster plays a filmmaker who proposes to his girlfriend only to be framed for the theft of her father's watch. He has always wanted to be a detective and becomes one in order to crack the case and to regain his lady's trust. "Sherlock Jr." is in the public domain, so you can find the full feature easily online. 

"Duck Soup" 

Movie makers were cranking out flicks with full audio by 1933 and this was good news for intellectual comedy stars like the Marx Brothers. Groucho Marx plays Rufus T. Firefly, a man who becomes the dictatorial president of the financially ruined nation of Freedonia. Mrs. Teasdale (Margaret Dumont) offers some of her fortunes as a bailout and insists on installing Firefly, a zany fellow, as the nation's new leader. Firefly falls in love with Teasdale, but so does the ambassador of the neighboring nation of Sylvania. War breaks out between the two nations over the love of this wealthy widow. 

"Abbott and Costello Go to Mars"

Bud Abbott and Lou Costello play laboratory technician Lester and orphan Orville, two dudes who board a rocket and accidentally launch it. The rocket is supposed to go to Mars, but instead lands in the middle of Mardi Gras. The wildly dressed festival goers apparently look like they're from Mars and the slapstick duo mistake them for Martians. Two prison escapees named Harry the Horse (Jack Kruschen) and Mugsy (Horace McMahon) steel a pair of space suits from the rocket and rob a bank. When the heat comes down, the two robbers hijack the rocket with Lester and Orville in it. The four lads land on Venus, a planet full of lovely woman where men were long since banished. Then they stir up nothing but trouble and get the boot. 

"Police Academy"

Hugh Wilson directed this zany slapstick comedy from 1984. A metropolitan mayor decides to scrap most of the requirements for becoming a police officer and this leads to utter chaos. Retired football star Bubba Smith plays a towering florist who becomes a police cadet. Steve Guttenberg plays a parking lot attendant who joins the academy to stay out of jail. These two are joined by a gun crazed lunatic, a mischievous character who makes sound effects with his mouth, a meek voiced woman who can only speak up when sticking a gun in someone's face and other social misfits. The academy instructors and chief take issue with this herd of crazies and do anything possible to make them quit.