I loved the film Atonement. I thought the acting was very good, and I enjoyed that period in history and James McAvoy played his part well. The only irritating thing for me was the way Keira Knightley walked so quickly all the time as though she was in a desperate hurry, even when she was supposed to be having a stroll in the garden! All-in-all, I enjoyed this movie very much, and Vanessa Redgrave fitted the part of the much older Briony very well

Hi... Yes I agree here it is difficult to name one... depending on what sort of movies you are talking about...

...impossible just one... HAPPINESS (Tod Solonz), MAGNOLIA (Paul thomas Anderson), SHORT CUTS (Robert Altman), MISTERY TRAIN, NIGHT ON EARTH, COFFEE AND CIGARETTES, DOWN BY LAW...(Jim Jarmusch), AMERICAN SPLENDOR (Berman-Pulcini), GHOST WORLD (T Wzigoff), FACES (John Cassavettes), MY IDAHO PRIVADO, DRUGSTORE COWBOY (Gus Van Sant), WONDER BOYS (Curtis Hanson), THE FISHER KING, TIDELAND, 12 MONKEYS (T Gilliam), BLUE VELVET, ERASERHEAD, STRAIGHT STORY (David Lynch), TRAINSPOTTING (Danny Boyle), THE CLOCK WORK ORANGE (Stanley Kubrick), ED WOOD (Tim Burton), FUNNY GAMES, LA PIANISTE (M Haneke), BREAKFAST ON PLUTON (Neil Jordan), C.R.A.Z.Y. (J M Vallée), TIME (Kim ki Duk), THE SCIENCE OF SLEEP, SUNSHINE ETERNAL OF THE SPOTLESS (Michael Gondry), CRASH (Croenenberg), FARGO, ARIZONA BABY, THE BIG LEBOWSKI (Bros. Coen)... and so on to infinite and beyond!!!

Hm, it's difficult to name just one. I'd let it be "The Colors of Paradise" (Rang-e-Khoda). It's an Irani movie about a blind boy. It's simple yet profound. An awesome piece of work from Majid Majidi.