Avatar dominates US box office
The film, reportedly the most expensive movie ever made, has made more than $352 million since its release three weeks ago.
Avatar is Cameron's first film since 1997's Titanic, the biggest modern blockbuster which netted $1.8 billion worldwide.
Guy Ritchie's Sherlock Holmes kept its position at the second spot, while Alvin And The Chipmunks: The Squeakquel at number three and It's Complicated at number four also retained their previous positions.
The Blind Side, which stars Sandra Bullock, took the fifth spot, making box office history as Bullock became the only actress ever to surpass the domestic $200 million mark with a film marketed with her name solely above the title.
Did You Hear About the Morgans?, starring Sex and the City's Sarah Jessica Parker and Hugh Grant, filled the eighth position, while Nine took the ninth spot.
Clint Eastwood's Invictus rounded off the list.