7. Lifeboat (1944)
Stars: Hume Cronyn, Mary Anderson, William Bendiz, Tallulah Bankhead, Walter Slezak, John Hodiak, Henry Hull, Heather Angel, Canada Lee
Films don't get much simpler than Lifeboat: It's literally about people stuck on a floating dingy, one of whom is part of the group that sunk their boat. And for the majority of Lifeboat's 100-minute running time, Hitchcock's camera never leaves the tiny vessel.
For lesser-talented directors, having to find multiple ways to derive tension from such closed quarters over a long period of time would prove overwhelming, but not for the always resourceful Hitchcock. Fully confident in his characters, he constantly shifts sympathies and alliances with every extended exchange of dialogue, so much so that by the film's third act, you're left unsure who to root for but also know that Lifeboat more than deserves your unending deliberations.