Shadow of a Doubt (1943)

Story:
A charming killer hides out in his relatives’ small hometown, where he befriends his favorite niece and namesake – who begins to suspect that he may be the famed Merry Widow murderer.
Source: Amazon Prime

Alfred Hitchcock’s earliest classic — and his own personal favorite — deals its flesh-crawling thrills as deftly as its finely shaded characters.
Rotten Tomatoes Critics Consensus

Major accolades received by Shadow of a Doubt (1943)

Featured in Roger Ebert’s Great Movies list.
Included among the 1001 Movies You Must See Before You Die.
Selected for preservation in the United States National Film Registry by the Library of Congress as being “culturally, historically, or aesthetically significant”.