Robin Williams was a comedian and actor of diverse talents. He was slapstick in Flubber and Patch Adams, menacing in One Hour Photo and Insomnia and stern yet earnest in Dead Poets Society.
At the root of each of Williams' performances was a boundless energy. In his comedic roles his characters surpressed a layer of melancholy (not least Aladdin's lonely Genie) while his straight performances always seemed like they could erupt into comedy (so much so that you can see the effects of the camera man shaking with laughter in this clip from Good Will Hunting).
Arguably though, the root of all Williams' performances was his incredible improvisation ability, a talent he perfected on the stand-up circuit and eventually fed into his first major television role on Mork & Mindy.
In this 2000 clip from Whose Line Is It Anyway?, Williams lets fly a torrent of high-octane comedy – from skits on "Paranoid Man" to a take on "what Robin Williams is thinking right now" that is often leftfield, but always hilarious.
So tonight, while you're lining up that Jumanji, Good Morning Vietnam and Mrs. Doubtfire marathon, take a few moments to appreciate Williams at his unscripted best.
Share your favourite Robin Williams moments below