"Nanu Nanu" and "O Captain, my Captain": Robin Williams will best be remembered by the characters he played and lines he delivered.
"I am Mork from Ork, na-nu na-nu." Robin Williams' breakout role was as happy alien Mork on the TV show "Mork and Mindy," a spin-off of "Happy Days." He played Mork, and is seen sitting on set here in April 1978.
Williams' Mork and Pam Dawber's Mindy were one of the most unlikely super-couples of the 1970s. They even eventually had a child, Mearth -- hatched from an egg laid by Mork and played by veteran funnyman Jonathan Winters.
In "Dead Poets Society," Williams played English teacher John Keating, who dared his class to take risks and break out of the molds their families may have put them in. He encouraged his students to call him "O Captain! My Captain!"
Robin Williams played the title role in "Mrs. Doubtfire." In a TODAY interview at the time, Robin Williams told Gene Shalit that creating his character had a lot to do with the makeup he wore. In April 2014, there were reports that Williams would reprise his role in a sequel.
Williams, right, next to Matt Damon, won an Academy Award for Best Supporting Actor in 1998 for his role in "Good Will Hunting."
In the 1995 fantasy-adventure film "Jumanji," Williams is chased by a lion, fights off giant spiders and is sucked into quicksand-like floorboards.
Williams played President Teddy Roosevelt in the "Night at the Museum" trilogy. He finished shooting the third film, "Night at the Museum: Secret of the Tomb" earlier this year. It's set to be released Dec. 19.
In 1997's "Flubber," a remake of the 1961 Disney comedy "The Absent-Minded Professor," Williams played a professor with an ingenious, if trouble-prone, invention.
In the 1991 Steven Spielberg movie "Hook," Williams played a lawyer who must reclaim his past as Peter Pan, with Dustin Hoffman as the menacing Captain Hook.
"One Hour Photo" may have been Williams' most surprising film. In the 2002 psychological thriller, the usually affable Williams portrays a disturbed photo clerk with a creepy secret.
"Aladdin" was the title character, but it was Williams' comic Genie who stole the show in the 1992 Disney film.
The DJ Williams played in 1987's "Good Morning Vietnam" was based on a real Vietnam War soldier, but much of Williams' radio banter in the film was improvised by the actor himself.
Williams starred with Sarah Michelle Gellar on the sitcom "The Crazy Ones," which ran from 2013-2014 before being canceled. Williams played an eccentric ad executive and Gellar his daughter.
Williams was strong to the finish, 'cause he eats his spinach, when he played the iconic comic-strip tough-guy in the 1980 big-screen version of "Popeye."