"Guardians of the Galaxy" topped the box office, beating out "Teenage Mutant Ninja Turtles" and newcomers "If I Stay" and "Sin City: A Dame Kill For."

With a lack of tentpole titles, the Marvel film took first place in its fourth weekend of release. "Guardians of the Galaxy made $17.6 million and brought its total to $251 million. The superhero picture topped "Transformers: Age of Extinction" as the highest grossing film of the summer and is now on track to become the highest grossing film of the year by passing Marvel's "Captain America: The Winter Soldier." "Guardians of the Galaxy" could also top the $300 million mark if it continues to hold as well as it has for the past four weekends.

In second place, "Teenage Mutant Ninja Turtles" brought in $16.8 million in its third weekend. The reboot has been one of the big surprises of the summer, even though it obtained bad reviews. Having already made $145 million, "TMNT" is on track to make $180 million by the end of its run.

"If I Stay" landed in third place with $16.3 million. The Chloe Grace Moretz romance drove young female audiences to the movie theaters but was unable to score the same success as "The Fault in Our Stars." With no big competition on the way, it should be able to end its run with at least $45 million to $50 million.

"Let's Be Cops" landed in fourth making another $11 million. While the film scored terrible reviews, it has already made a solid $45 million and could be on the road to making $75 million.

In fifth, the newcomer "When the Game Stands Tall" opened with $9 million. The gross was a bit lower than recent sports movies "Million Dollar Arm" and "Draft Day." Tristar attempted to market the movie as Christian based as well as a sports movie. However, the marketing always lacked a clear focus, and there were no clear A-List actors.

In their second weekends, "The Giver" and "The Expendables 3" continued to disappoint. The Giver dropped 45 percent and brought $6.7 million. It has now made $24 million and could end its run with $40 million.

Meanwhile, "The Expendables 3" had a 58 percent fall and only grossed $6.6 million. The actioner has only grossed $27 million in its two weekends, and that is still less than opening weekend of the second installment.

In eighth place, "Frank Miller's Sin City: A Dame to Kill For" crashed with $6.4 million in its opening weekend. The gross was down 78 percent from when the original installment bowed in 2005. The reason for the lack of enthusiasm in this new installment was the nine-year gap between the two films and the fact that three major roles were recast. Additionally, reviews were far worse than 2005's "Sin City."

The disastrous opening marks the third-lowest debut for director Robert Rodriguez. With little marketing, this comic adaptation is likely to end its run with less than $20 million.

In art house cinemas, "Love is Strange" debuted with $127,000. Having opened in five theaters, the LGBT drama averaged an outstanding $25,400 per theater average. With great reviews, strong word-of-mouth and awards buzz, Sony Pictures Classics will expand the romance in the coming weeks.

Radius TWC had mixed results with "The One I Loved." The film opened to $55,100 in nine theaters. Radius TWC has had the comedy on VOD for the past weeks, and this may have been the reason for the disappointing opening.

Indie holdover "Boyhood" continued to capture audiences as it brought in another $1.8 million in 734 theaters. The Richard Linklater drama has now made $16.5 million and is still on track to make $20 million. The coming-of-age story, which was filmed over 12 years, has had a strong response from audiences and critics and is being hailed as the best film of the year.

Woody Allen's "Magic in the Moonlight" continued to wane after its nationwide expansion. The comedy only made $1.3 million and has only made $6.8 million in its fifth weekend.

Roadside Attractions started decreasing theater count on "A Most Wanted Man." However, the mover still managed to make $921,000 in 433 theaters. The Philip Seymour Hoffman starrer has now made $14.1 million, and word-of-mouth continues to be strong.