The Character: OK, a bit of cheat, but really it’s impossible to single out the most insane member of the Brewster family, although they can be ranked in order of harmfulness.

In Frank Capra’s spookily dark (and, yes, hilarious) comedy (adapted from the stageplay of the same name), Cary Grant’s Mortimer Brewster visits his family to inform them of his recent nuptials. His brother Teddy’s affliction only extends to the belief that he’s Theodore Roosevelt, while his aunts have picked up an awfully nasty habit of offing ageing bachelors for their own good. Most sinister is the other brother (and Frankenstein lookalike) Jonathan, a practising murderer.

Jonathan’s creepiness is increased no end by the presence of his sidekick, Dr Einstein, played in utterly sleazy style by Peter Lorre.

Craziest Moment: “Insanity runs in my family... It practically gallops,” explains an end-of-his-tether Mortimer.