What should have won: Dogville
What actually won: Elephant
This was a pretty strong year at Cannes, but almost everyone was surprised when Gus Van Sant's Elephant beat more heavily favoured contenders like Mystic River and Dogville. Van Sant's Columbine massacre-inspired film might have started people talking, but it's low key to the point of stasis and an intensely frustrating watch. You'll find few people who have actively sought it out since - whereas Eastwood's Mystic River, for example, went on to Oscar glory.