Alfred Hitchcock defined himself in 1934-1935. Although he was an established director with specialty in tense filmmaking, these years saw him go from being a director to the Alfred Hitchcock. In 1934 his original version of The Man Who Knew Too Much established one of Hitch’s main career touchstones: the innocent man swept up in a world of intrigue.
While a great film (though I prefer the remake, singing and all), The Man‘s formula got a tweak with 1935’s The 39 Steps. The tense spy drama was blended with just a bit of wry levity and a liberal dose of romantic meet-cute (where ‘cute’ means ‘handcuffed together’, I guess).
Murder! Mystery! Treachery! Romance! How many of Hitchcock’s classics would that describe? Probably not Psycho, but still quite a few of the others.