LOS ANGELES (AP) — There was no mystery at the weekend box office. Robert Downey Jr.’s “Sherlock Holmes: A Game of Shadows” debuted as the clear favorite with $39.6 million.
The family sequel “Alvin and the Chipmunks: Chipwrecked” opened a distant No. 2 with $23.3 million.
The top 20 movies at U.S. and Canadian theaters Friday through Sunday, followed by distribution studio, gross, number of theater locations, average receipts per location, total gross and number of weeks in release, as compiled Monday by Hollywood.com are:

1. “Sherlock Holmes: A Game of Shadows,” Warner Bros., $39,637,079, 3,703 locations, $10,704 average, $39,637,079, one week.
2. “Alvin and the Chipmunks: Chipwrecked,” Fox, $23,244,744, 3,723 locations, $6,244 average, $23,244,744, one week.
3. “Mission: Impossible — Ghost Protocol,” Paramount, $12,785,204, 425 locations, $30,083 average, $13,385,204, one week.
4. “New Year’s Eve,” Warner Bros., $7,310,413, 3,505 locations, $2,086 average, $24,716,167, two weeks.
5. “The Sitter,” Fox, $4,608,681, 2,752 locations, $1,675 average, $17,929,987, two weeks.
6. “The Twilight Saga: Breaking Dawn — Part 1,” Summit, $4,197,893, 2,958 locations, $1,419 average, $266,327,974, five weeks.
7. “Hugo,” Paramount, $3,707,848, 2,532 locations, $1,464 average, $39,155,709, four weeks.
8. “Arthur Christmas,” Sony, $3,554,286, 2,929 locations, $1,213 average, $38,501,631, four weeks.
9. “The Muppets,” Disney, $3,520,926, 2,808 locations, $1,254 average, $70,994,571, four weeks.
10. “Young Adult,” Paramount, $3,403,159, 986 locations, $3,451 average, $3,843,083, two weeks.