Memorial Day is one of the busiest movie weekends of the very lucrative summer season, and two established franchises will compete to top the box office. “The Hangover Part III” and “Fast & Furious 6” will be competing with “Star Trek Into Darkness,” “Iron Man 3” and “The Great Gatsby."

“Star Trek Into Darkness” is the reigning box-office champion, but its $70 million gross has been considered a disappointment by many experts. While critical and audience response have been positive, it appears the new “Star Trek” movie will not be able to hold on to the top spot as “The Hangover Part III” and “Fast & Furious 6” look poised to be the big Memorial Day winners.

In the battle of the two new movies, “Fast & Furious 6” appears to be the front-runner to win the weekend. The latest installment of the franchise is directed by Justin Lin, who has directed the previous three movies in the series. “Fast 6” brings together some familiar faces, including Vin Diesel, Dwayne “the Rock” Johnson, Paul Walker, Ludacris (Christopher Bridges), Michelle Rodriguez and Tyrese Gibson.

The box office battle between “Fast 6” and “The Hangover Part III” has yet to be decided, but the critical debate belongs to the latest “Fast” movie. The movie has garnered a 75 percent fresh rating on Rotten Tomatoes with many critics applauding the fantastic action sequences while giving the film credit for taking its story, as well as franchise continuity, seriously but not so serious as to drown out the fun of fast cars and stunts.

Jen Chaney from the Washington Post says “Fast 6” does what it sets out to do: create a fun action movie and the “physics defying” car-related action sequences. Todd McCarthy from the Hollywood Reporter has similar praise. For McCarthy, the story is serviceable while setting up the next installment in the franchise. McCarthy also notes that “Fast 6” understands audience expectations and delivers on all fronts while increasing the ridiculousness of the action sequences.

While the “Fast & Furious” franchise will continue with a seventh movie, “The Hangover Part III” will serve as a finale for the Wolfpack. But fans may be disappointed in how the story ends for Alan, Phil and Stu. On Rotten Tomatoes, the film has a 22 percent rotten rating from critics, citing lack of quality jokes and an inane story with critics describing the third film in the “Hangover” franchise as a simple Hollywood cash grab. Stephen Farber from THR notes the unusual amount of animal cruelty on display in “The Hangover Part III,” noting several animals that occur throughout the movie.

The emphasis on the movie is on Alan, and, while Zach Galifianakis gets more to do in the film, including more character exploration of Alan, the film comes across as dull. Even positive reviews, such as the one from the Wall Street Journal’s John Anderson, describe “Hangover III” as an improvement from the second film, but there is little else to praise.

At the box office, the momentum is with “Fast 6,” with experts predicting the film to earn $100 million over the weekend. Variety is reporting estimates range from $85 million to $100 million based on strong buzz from social media, as well as positive critical reception.

“Hangover III” earned $3.1 million for late screenings on Wednesday, down from the $10.4 million grossed by the second film in its late night screenings in 2012, and Variety is expecting the film to follow in line with its predecessor, earning an estimated $65 million over the holiday weekend.

“Fast 6” and “Hangover III” are competing for the same audience demographic, notes Variety, and the studios hope there is enough money to go around during the holiday weekend. With current estimates, the box office is expected to reach record highs, Variety reports.