Lets not forget he also played the lead in "The Forbiden Planet". Perhaps one of the most influential sci-fi films ever. Airplane though I think is the funiest film of all time. Just seen the news of his passing on the BBC news website. It just reminded me off this line from Airplane for some reason.
"Yes, he looked at me and said, "Doc," he said, "Some time, when the crew is up against it, and the breaks are beating the boys, tell 'em to get out there and give it all they've got. And win just one for the Zipper. I don't know where I'll be then Doc, he said. But I won't smell too good, that's for sure."
R.I.P