Many will remember him as Uncle Ben in the Spider-Man movies, or even as Shame on the old Batman series. Perhaps some will note his performance in Charly, or even his involvement in fighting a check forging scandal.
Personally, I've always liked his television work in the early 1960s, especially on The Twilight Zone ("One Hundred Yards Over the Rim" and "The Dummy" and The Outer Limits ("The Galaxy Being").
The following videos are offered in tribute. Enjoy.