As the world mourns Williams, let's look back at the roles that made the actor so beloved.
Mork, Mork & Mindy
Playing an alien sent from the planet Ork to study humans, Williams brought his comedic sensibilities to a national audience for the first time. The catchphrases ("Nanu nanu") may seem odd to contemporary viewers, but Williams's mile-a-minute comic deadpan is instantly recognizable.
Garp, The World According to Garp
Williams's ambition was evident in his first major film role. Rather than repeat his Mork persona, he took the lead in the screen adaptation of John Irving's classic novel, a contemplative author wrestling (sometimes literally) with notions of family and sexuality.
Adrian Cronauer, Good Morning Vietnam
Williams received his first Academy Award nomination for playing Cronauer, an irreverent radio broadcaster who entertained troops during the Vietnam War. The film's broadcast scenes proved that his manic improvisations could work in a "serious" picture.
John Keating, Dead Poets Society
The warmth and force of Williams's comic energy separated this period piece from the rest of the "inspirational teacher" genre, as his poetry-loving lecturer inspired a generation of students to stand up for their beliefs (and stand on their desks).
Peter Pan, Hook
Even as he approached middle age, Williams delighted in letting out his inner teenage boy, making him the perfect choice to play the adult version of the boy who refused to grow up.
For a generation of '90s kids, this is the definitive Williams performance. Thanks to the power of animation, for the first time, the actor's physical form could keep up with his voice.
Daniel Hilliard, Mrs. Doubtfire
The physical transformation required for Mrs. Doubtfire was no less impressive. Even under a foam suit, a wig and a prosthetic mask, Williams's personality could not be contained.
Armand Goldman, The Birdcage
Williams's love of camp made him stand out among his comedic peers, and playing the straight man (so to speak) to Nathan Lane gave him the opportunity to indulge his wilder instincts while also offering up a grounded performance.
Sean Maguire, Good Will Hunting
(Warning: Some NSFW language)
After two nominations, Williams won his sole Oscar for playing a quiet therapist who helps Matt Damon overcome his insecurities. As the dispenser of wisdom both obvious ("It's not your fault") and uncomfortable ("I can't learn anything from you I couldn't read in some book"), Williams proved the perfect mentor for Damon's troubled genius.
For more on Robin Williams's tragic death and his legacy of comic genius, pick up the latest issue of PEOPLE, on newsstands Friday
If you or someone you know is considering suicide, please contact the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).
The Williams family is asking well-wishers to send contributions to charities close to the actor's heart in lieu of flowers. Suggested organizations include St. Jude Children's Research Hospital, Challenged Athletes, USO, the Muhammad Ali Parkinson Center, the Christopher and Dana Reeve Foundation and Glide Memorial Church in San Francisco.