I got tired of Robin Williams' schtick decades ago, but only because I was immersed in it for so many years. People would remark: "Wow, how can anyone could think so fast?" I would recite how his "quick" off-the-cuff jokes were actually rehearsed and already used in that interview or that concert or these other two talk shows. I caught everything I could. It was terrific. Then I hit saturation point, and pretty much stopped watching his rat-a-tat-tat comedy bits with rhythms I had already absorbed and moved on.
I fucking owned the Mork from Ork suspenders. I wore them until 12 years old. We friends greeted each other in grade school with "nanu, nanu". We repeated bits from Mork & Mindy the next day at school, and into the week, and the next week. Okay. Got that out.
As a subdued actor, he was much better to me. Like his comedies, some huge, awful misses, but also performances that were impressive. I know the cool thing nowadays is to think of Good Will Hunting as mawkish. But he was good in that movie. And in Dead Poets Society (something I avoid as more mawkish than Hunting). And, a movie I've watched 5-6 times to try to get precise about why/how it went wrong ... Hook. Spielberg whiffed that movie. Williams is good in a role he worried he'd be called "Porky Pan". There was no way to play that role and be great, but he showed courage taking it on. He's particularly good as Peter Banning, before discovering he was Peter Pan.
But the movie that I appreciate him the most for is The World According to Garp. My parents took me to see it in a movie theater. I was only 13. A lot of jokes were over my head, but the sense of the world wasn't. The irony wasn't. The hurt wasn't. And it got me into reading modern literature. I went straight from reading the Dune books (I don't like sci-fi, but it was a perfect series for a horny early teen cynic) to reading John Irving. I rarely read fiction written by living authors, even then. But I read Garp twice. I've seen the movie 4-5 times, and am moved each time. Enraged at the Ellen Jameseans, amused and taken by John Lithgow's performance as a former NFL player turned to a woman, Glenn Close's oddly clinical yet warm performance.
And, except for a few scenes where he got to be rat-a-tat-tat in Garp, Robin Williams' performance is subdued and sly and engaging. As a writer, married to a literature professor. In Williams' often frantic display of frenetically vibrating strings and wavelengths, he often pointed us to nodes of calm. It is those points where I'll think about him the most, and where he showed us the most.