Coleman's line about Broderick being ideal for KGB recruitment brought howls of laughter in the theater.
Probably the best of the "tired/depressed/guilt-ridden scientist" performances in the genre is that of Fred Astaire in On The Beach. His drunken rant at a cocktail party is totally believable, he completely "sells" the character. Overall, his performance probably edges out that of Gregory Peck in the film.