Having lived through 1984 in real time, I remember there being three obvious choices for the best picture award come Oscar time—Amadeus, A Passage to India and The Killing Fields. For me at least, none of them have really held up on repeat viewings.
Instead, I'm going with a couple of crowd-pleasers, The Terminator and This is Spinal Tap, which for all their low-budget limitations, are very nearly perfect and have entered the popular consciousness in way those other three films haven't.
(By the way, whenever I see The Terminator, I think what a pity that director James Cameron ever became so successful that he was allowed to work with unlimited budgets. Like many artists, limits forced Cameron to think creatively to realize the vision in his head. Without limits, his films have become increasingly bloated, obvious and, for me at least, much less interesting. But I digress.)
winner: The Terminator (prod. Gale Anne Hurd)
winner: This Is Spinal Tap (prod. Karen Murphy)
PICTURE (Foreign Language)
winner: Un dimanche à la campagne (A Sunday in the Country) (prod. Bertrand Tavernier)
winner: Harry Dean Stanton (Repo Man and Paris, Texas)
winner: Steve Martin (All of Me)
winner: Judy Davis (A Passage to India)
winner: Kathleen Turner (Romancing The Stone)
winner: James Cameron (The Terminator)
winner: Rob Reiner (This Is Spinal Tap)
winner: M. Emmet Walsh (Blood Simple)
winner: Peggy Ashcroft (A Passage to India)
winner: Christopher Guest, Harry Shearer, Michael McKean and Rob Reiner (This Is Spinal Tap)