Rope

Rope is a 1948 Hitchcock movie starring James Stewart, John Dall, Farley Granger, Joan Chandler, and Sir Cedric Hardwicke. Wikipedia says it's "notable for taking place in real time and being edited so as to appear as a single continuous shot through the use of long takes". This is a classic.

trailer:

The Guardian says, "Hitchcock delights in toying with his audience, repelling and luring his viewers into the scene of a crime – and nowhere more audaciously than in Rope". The NYT has two reviews: one from the time of its release and another from 1984.

Slant Magazine gives it 3.5 out of 4 stars. Roger Ebert says, "“Rope” remains one of the most interesting experiments ever attempted by a major director working with big box-office names, and it’s worth seeing". Rotten Tomatoes has a critics score of 97%.