The first character that comes to mind when I think of a trademark hat is, of course, Indiana Jones, as played by Harrison Ford.
Another famed fedora-wearer is Humphrey Bogart, who sported the hat in such films as Casablanca, The Maltese Falcon, The Treasure of the Sierra Madre, The Big Sleep, and Sabrina.
Similar to Bogey, John Wayne made a series of movies in which he wore a series of similar hats - in Wayne's case, cowboy hats.
Hatmaker Resistol, which provided some of Wayne's hats for his movies, still carries a line of seven hats inspired by the actor.
Jacqueline Kennedy brought not only the pillbox hat into prominence in the early 1960s, but also its designer, Halston.
One of the most famous hat-wearers in current history is not known for a particular style of hat so much as hats in general: Queen Elizabeth II.
Another British leader who was quite fond of hats was Sir Winston Churchill, who sported many different styles over the years, but whose trademark hat was undoubtedly the homburg.
One celebrity who is famous for a hat that she really only wore that one time is Mary Tyler Moore, who is well known for tossing her hat into the air during the opening credits of The Mary Tyler Moore Show.
yesterday's blog entry for the definition of both hat styles). Although the opening sequence was slightly changed every season, they always ended with that same hat toss clip, freezing on Mary's beaming face with the hat in mid-air. Ever since Mary's exuberant toss, people have been recreating that moment on the streets of Minneapolis near the Nicollet Mall, where the original sequence was filmed. The bit has been parodied dozens, perhaps hundreds of times since, but one of the funniest was in the closing credits of the spinoff, Rhoda, in which Rhoda attempts to recreate the hat toss on the streets of New York City, but drops her hat.
Perhaps the creepiest trademark hat ever is the bowler (or derby, in American terms) worn by Malcolm McDowell as the sociopathic Alex DeLarge in the film A Clockwork Orange.
A much more light-hearted example of a strong contrast between the formality of a hat and the style of the famous wearer is the case of Harpo Marx.
One of the most well-known literary characters to be associated with a specific (and somewhat unusual) type of hat is Sherlock Holmes and his deerstalker.
Another notable hat-wearing character which has been played by multiple actors, is Dr. Who. Each incarnation wears a unique ensemble, but Matt Smith's Doctor is known for pairing his tweed jacket with a red bowtie and a distinctive fez.
Other famous hat wearers:
Crocodile Dundee (film character played by actor Paul Hogan) - Australian cattleman hat (ornamented with crocodile teeth)
Pharrell Williams (singer/songwriter) - a style by designed Vivienne Westwood called "Buffalo Girls (Nostalgia of Mud)"
Slash (lead guitarist of Guns N' Roses) - top hat
Abraham Lincoln (U.S. President) - stovepipe hat (top hat)