"There were so many different things that he was able to do," says Fandango's Dave Karger. "Nothing seemed out of his reach, professionally."
He first grabbed America's attention in the late 1970s when the role of the wacky alien on "Mork and Mindy" gave williams' gift for improvisation a welcome playground.
"He just sort of commanded the room, commanded the energy, and took a scene into directions that
no one saw coming," recalls Entertainment Weekly's Thom Geier.
Williams' TV stardom carried into movies.
One of his earliest was "Moscow on the Hudson".
"What I remember is what everybody does, that met him and knew him. He was one of the most gentle men that I've met in my life," says co-star Maria Conchita Alonso.
Williams made audiences laugh in outrageous box office hits, but quieter dramas such as "Dead Poets Society" brought critical praise and "Good Will Hunting" earned him an Oscar.
"He really, like many comic actors, had a deep well of sadness that he was able to project on the screen," Geier notes.
A third "Night at The Museum" is among several films Williams recently completed that will release in the coming months.