Leonardo DiCaprio and Marion Cotillard in 'Inception''Inception' has triumphed at the box office for a third straight week, becoming only the third movie this year to three-peat (after 'Alice in Wonderland' and 'Shrek Forever After'). It won despite the addition this week of three new wide-release movies, one of which ('Dinner for Schmucks') did very well, opening strongly in second place, as the other two ('Cats & Dogs: The Revenge of Kitty Galore' and 'Charlie St. Cloud') fell by the wayside.

'Inception,' which really hasn't had a slow day since it opened on July 16, won this week's contest with an estimated $27.5 million. Despite competition from the new releases and from fellow action attraction 'Salt,' its business fell only a third from last weekend. Thanks in large part to repeat business from viewers trying to untangle its plot, the sci-fi thriller has grossed $193.3 million in 17 days, with the $200 million mark likely to fall Monday or Tuesday. Leonardo DiCaprio and Marion Cotillard in 'Inception''Inception' has triumphed at the box office for a third straight week, becoming only the third movie this year to three-peat (after 'Alice in Wonderland' and 'Shrek Forever After'). It won despite the addition this week of three new wide-release movies, one of which ('Dinner for Schmucks') did very well, opening strongly in second place, as the other two ('Cats & Dogs: The Revenge of Kitty Galore' and 'Charlie St. Cloud') fell by the wayside.

'Inception,' which really hasn't had a slow day since it opened on July 16, won this week's contest with an estimated $27.5 million. Despite competition from the new releases and from fellow action attraction 'Salt,' its business fell only a third from last weekend. Thanks in large part to repeat business from viewers trying to untangle its plot, the sci-fi thriller has grossed $193.3 million in 17 days, with the $200 million mark likely to fall Monday or Tuesday.

'Schmucks,' opening in 2,911 venues, wasn't the widest new release of the week (that would be 'Cats & Dogs), but it was the best reviewed. The comedy's estimated $23.3 million debut fell just shy of the $25.2 million opening of Steve Carell's last live-action comedy, April's 'Date Night,' but it still did very well considering how much competition there was (including from Carell's own cartoon 'Despicable Me,' still going strong in its fourth week). For Paul Rudd, however, $23.3 million represents a career-high debut as a leading man.

'Salt' held up well, finishing third even though it lost nearly half of last week's business. It took in an estimated $19.3 million, for a 10-day total of $70.8 million. 'Despicable Me,' despite a lot of competition from other family films, remained the top kid-friendly choice, losing just a third of last week's business to take in another $15.5 million, good for fourth place on the chart.

'Cats & Dogs: The Revenge of Kitty Galore''Cats & Dogs: The Revenge of Kitty Galore' was widely predicted to open around $18 or $19 million. It's playing on 3,705 screens, it's raking in a 3-D surcharge on many of those screens, it's the sequel to a hit movie (2001's 'Cats & Dogs') and it's the newest family film available. Unfortunately, there are a lot of other strong family films still playing ('Despicable Me,' 'Toy Story 3,' 'The Sorcerer's Apprentice,' and 'Ramona and Beezus'), and the original movie played before much of the sequel's target audience was born. The film barely mustered a fifth-place finish with an estimated $12.5 million opening, about half what the original earned when it opened nine years ago. It scored the lowest opening of any 3-D non-concert film since 'Coraline' opened to just under $17 million more than a year ago. It's also only the fifth movie opening on more than 3,500 screens to eke out less than $14 million its first weekend. The film seems poised to join this summer's earlier talking-pet flop 'Marmaduke' (which has earned just $32.9 million in nine weeks) in the unwanted animal pound.

A hair behind 'Cats & Dogs' was 'Charlie St. Cloud,' in sixth place with an estimated $12.1 million debut. It opened on 2,718 screens and featured Disney-bred heartthrob Zac Efron, but the movie's glum topic (Efron plays a young man unable to get past his little brother's accidental death) led to a debut even below the $14-$15 million pundits had projected.

The full top 10:
1. 'Inception,' $27.5 million (3,545 screens), $193.3 million total
2. 'Dinner for Schmucks,' $23.3 million (2,911), new release
3. 'Salt,' $19.3 million (3,612), $70.8 million
4. 'Despicable Me,' $15.5 million (3,602), $190.3 million
5. 'Cats & Dogs: The Revenge of Kitty Galore,' $12.5 million (3,705), new release
6. 'Charlie St. Cloud,' $12.1 million (2,718), new release
7. 'Toy Story 3,' $59.0 million (2,105), $389.7 million
8. 'Grown Ups,' $4.5 million (2,269), $150.7 million
9. 'The Sorcerer's Apprentice,' $4.3 million (2,524), $51.9 million
10. 'The Twilight Saga: Eclipse,' $4.0 million (2,334), $288.1 million

Top 10 movies of summer 2010:
1. 'Toy Story 3,' $389.7 million
2. 'Iron Man 2,' $311.4 million
3. 'The Twilight Saga: Eclipse,' $288.1 million
4. 'Shrek Forever After,' $235.6 million
5. 'Inception,' $193.3 million
6. 'Despicable Me,' $190.3 million
7. 'The Karate Kid,' $172.9 million
8. 'Grown Ups,' $150.7 million
9. 'The Last Airbender,' $127.2 million
10. 'Robin Hood,' $105.2 million

•Follow Gary Susman on Twitter @garysusman.