James Stewart would have been 100 years old today. Stewart was one of the screen's greatest natural actors. Little in the way of scandal entered his life (an affair with Grace Kelly has always been speculated-- hard to judge anyone on that though, if it were true!).
His most well-known roles are his performances for Frank Capra and Alfred Hitchcock— and these are possibly his best. He was overlooked for an Oscar for Mr. Smith Goes to Washington, so they gave it to him the next year for The Philadelphia Story (this make-up Oscar tradition began with Bette Davis' win for Dangerous following her slight for Of Human Bondage). And Mr. Smith is a tour de force for Stewart ("I guess this is just another lost cause Mr. Payne.") topped only by It's A Wonderful Life (the post WWII maturity having sunk into Stewart). The war years gave Stewart the depth to make the Anthony Mann westerns in the 1950s.
His four Hitchcocks— Rope, Rear Window, The Man Who Knew Too Much, and Vertigo— represent a tremendous range. Would it not been for Stewart, Hitchcock's Vertigo might not be vying for Sight and Sound's #1 slot... the upsetting of Citizen Kane is on the horizon for 2012.
When I came to Los Angeles, Stewart was still alive and he was #1 on my list to see in person-- it never happened. I went to see An American Tail: Fievel Goes West specifically because it was Stewart's first movie "role" in years. When it turned out to be his swan song, it became my only Stewart movie seen theatrically.
Like Orson Welles is inextricably attached to those "sell no wine before its time" ads in his last years, Stewart was all about those poems he read on Carson in the '80s. Here's one from YouTube, the one about his dog (if you know any of them it's this one):
Someone also posted his What's My Line? appearance (of course the panel gets it in two minutes):