Dead Poets Society is one of my all time favorite movies in general and certainly one of my favorite roles to see Robin in. Amazing film and one of the few to have a character that uses my name as well (Neil) of course that guy too takes his life in the movie.
A lot of people look to comedians like Richard Pryor or Eddie Murphy and they are funny comedians but I liked the zany, crazy, fucked up that Robing brought. He pushed and tried to be uncomfortable. I idolized his approach to comedy as a kid as I was crude even then having 2 older brothers who thought it was cool to corrupt me early. I remember he did this skit on some sketch comedy show. I could probably Google it and figure it out but it doesn't matter. Robin was young and making a name for himself but he got to meet Frank Sinatra on the show and asked if he could shake his hand and upon doing so he goes totally screwball star struck and says "Oh man I'm so happy I could drop a log." and Sinatra just loses it...maybe I'll hit the youtubes and see if that clip exists somewhere. Cracked me the fuck up!
Despite admiring his darker roles, I'd have to go with his acting in Good Will Hunting as my favorite. It was only a week or two ago that I heard that he had improvised the lines about his wife farting in bed and how it's the small things you love and adore about a person. (Language warning on the scene below)
I have strong memories of when I was a kid being moved by various films depicting the horrors of the Vietnam War. 'Good Morning, Vietnam' was one of those films which juxtaposed his zany comedy with the tradgedies of war to create a very emotional reflection on that conflict. A perfect role for Robin that showcased his ability to do serious stuff too. Very sad to hear of his passing.
My favourite movie with robin williams is patch adams. The way he gets the girl of his dreams and also loses her again. Fantastic acting especially the childrens ward was an incredible movie moment for me.