THIS WEEKEND you'd do better with the repertory films than the heavy- hitters (Wall Street, Empire of the Sun and Throw Momma from the Train). Friday at noon, the National Archives will show Pare Lorentz's The River, his masterful portrait of the Mississippi River, which was first shown in Washington's Rialto Theater 50 years ago. It will be shown with Lorentz's 1936 The Plow That Broke the Plains, another poetic piece -- about America's Dust Bowl. The show is free, at the Archives theater at Eighth and Pennsylvania NW.

Friday night, the Biograph shows Hugh Brody's 1919 with D.C. favorite A Room With a View. Tuesday through Thursday it will screen Marcel Pagnol's trilogy -- Marius (1931), Fanny (1932) and Ce'sar (1936). Directed by Alexander Korda, Marc Allegret and Pagnol, respectively (but all written by Pagnol), the films are about characters living in the port of Marseilles. (Pagnol's "L'Eau des Collines," a two-part novel, was adapted by Claude Berri to make Jean de Florette and the upcoming Manon of the Spring.)

Saturday at 2 and Sunday at 6, the National Gallery's Andrei Tarkovsky film series continues with the 1979 Stalker. In this return to science fiction (after Solaris), a vast area called the Zone -- struck by a meteorite -- is closed off to everyone except guides, known as stalkers.

The American Film Institute is showing John Huston's magical adventure epic, The Man Who Would Be King, Saturday at 4 and Sunday at 6. Michael Caine and Sean Connery make one of the great all-time couplings and if you haven't seen it, now's the time. The AFI's also showing the Washington premiere of Amazing Grace and Chuck, an anti-nuclear war film starring Gregory Peck that never quite made it here (Saturday and Sunday at 6:30). Also at the AFI is Alan Parker's Birdy (Sunday 8:30, Monday at 6:30) with Nicholas Cage and Matthew Modine. And Terry Gilliam's tour-de-force Brazil -- a black comedy/sci-fi that suggests a combination of Jacques Tati's Playtime and Orwell's 1984 -- plays on Wednesday at 6:30 and Thursday at 8:30. Admission, as always, is $4.50 ($3.50 for members). Call 785-4600.

Sunday, Cabiria, the 1914 silent movie epic made by Giovanni Pastrone and hailed as a masterpiece by D.W. Griffith, will be shown at the University of Maryland's Adult Education center auditorium (University Boulevard and Adelphi Road). The original music score will be performed (live) by piano and organ, and the Italian intertitles will be translated by New York University professor Charles Affron. He'll also introduce the film. The free screening in the 700-seat auditorium is at 2:30.

Meanwhile, American University's College of Arts and Sciences and the Forum for the Psychoanalytic Study of Film will have two showings of Bernardo Bertolucci's The Last Emperor at the Mark Wechsler Theater at 1 and 7. The $8 fee ($4 for students) includes a 4:45 reception at American U.'s Mary Graydon Center. Call 333-8388 to reserve. The films will be introduced by Forum members Bruce Sklarew, T. Jefferson Kline, Gene Gordon, as well as American University film professor Jack Jorgens. But don't worry -- there will be no take-home exams.

Batteries Not Included, a comedy starring Hume Cronyn and Jessica Tandy, which opens next Friday, will have a free sneak preview Sunday. See the ads for showtimes.

The University of Maryland's Hoff Theater will show Fletch with cult favorite Highlander on Monday. On Tuesday and Thursday it's Ferris Bueller's Day Off with Lethal Weapon (those two films go so well together); and Wednesday, Sleeper and Running Scared. They're free. Call 454-2594 for times.

Instead of watching Throw Momma from the Train, see the real thing. Hitchcock's Strangers on a Train plays at the Library of Congress' Mary Pickford Theater, Thursday at 7:30. Call 287-5677 for reservations.