Thanks to Awards Daily for pointing this video out as someone has gone to the trouble of editing together all of Alfred Hitchcock‘s cameos from 27 (if my count was correct) of his films. The creator of the piece notes he has not included cameos from Easy Virtue (1927), Blackmail (1929), Foreign Correspondent (1940), Suspicion (1941), Spellbound (1945), The Paradine Case (1947) and Under Capricorn (1949).
Among my favorites are the one from To Catch a Thief and the wheelchair stand up from Topaz.