Productive weekend with no front runner.

The ComingSoon.net Box Office Report has been updated with studio estimates for the weekend. Click here for the full box office estimates of the top 12 films and then check back on Tuesday for the final figures based on actual box office.

Columbia Pictures' Paul Blart: Mall Cop topped the four-day Martin Luther King, Jr. holiday weekend with an estimated $39 million from 3,144 theaters. The Kevin James comedy, directed by Steve Carr, averaged an impressive $12,405 per site. The film surpassed Black Hawk Down ($33.6 million) to become the second-highest opening for the four-day weekend, trailing only last year's Cloverfield ($46.1 million). It cost just $26 million to make.

Dropping one spot to second, Clint Eastwood's Gran Torino added another $26.2 million over the four days to bring its total to $77.2 million. The Warner Bros. Pictures release carried a budget of about $33 million.

Lionsgate's horror remake My Bloody Valentine 3D debuted in the third spot to an estimated $24.2 million in 2,534 theaters, followed closely by Fox Searchlight's new biopic Notorious, which made $24 million in 1,638 theaters. The latter had the biggest per-screen average of the top 12 films with $14,652.

DreamWorks Pictures' new family comedy Hotel for Dogs rounded out the top five with $22.5 million from 3,271 theaters.

In their second weekends, 20th Century Fox's Bride Wars collected $14 million for a total of $39.9 million and Rogue Pictures' The Unborn earned $10.993 million for a total of $34.2 million.

Paramount Vantage increased the theater count for Edward Zwick's Defiance to 1,789 theaters, allowing the Daniel Craig, Liev Schreiber and Jamie Bell drama to enter the top 10 with $10.7 million. It has earned $11 million in three weeks.

The Golden Globe wins for Slumdog Millionaire gave the Danny Boyle-directed drama a nice push, as it collected another $7.2 million from just 582 theaters - an average of $12,285 per site. The film has earned $43.987 million and was produced for just $15 million.

Opening in limited release, Bollywood pic Chandni Chowk to China made $700,000 from 130 theaters.

Click here for the full box office results of the top 12 films