Family films are always a big part of the Thanksgiving box office equation, but this year multiplexes will be especially stuffed with the genre.

Three new PG-rated movies, all with good reviews, hit theaters in U.S. and Canada Wednesday: Disney's The Muppets, Paramount'/GK's Martin Scorsese film Hugo and Sony/Aardman's Arthur Christmas.

These movies join Warner's Happy Feet Two, which was released last weekend. DreamWorks Animation's Puss in Boots, which premiered in late October, will also have a few remaining play dates.

The five-day Thanksgiving holiday period is typically the biggest of the year at the box office. But there are a lot of newly released family movies playing at the same time this year, and the competition is thick.

Consider that over Thanksgiving weekqend in 2010, the only competition for Disney's Tangled was week No. 2 of Warner's Harry Potter and the Deathly Hallows - Part 1 and week No. 4 of DreamWorks' Animation's Megamind.

Tangled enjoyed a $68.7 million five-day haul, on its way to a $590.7 million total box office bounty. But it will take an exceptional over-performance for any of this week's films to come even close to that mark.

We don't expect to be No. 1, admitted an executive for one of the weekend's competing studios. He told TheWrap his company's strategic objective is to get its movie open for an extended holiday play.

He cited films like 2004's The Polar Express and 2009's A Christmas Carol, which endured disappointing openings but performed very well over ensuing holiday weekends.

I remember when 'Polar Express' opened a few years ago, and there was a rush to judgment in the press based on its opening, which was viewed as mediocre to middling at best, the executive said. Go back and look at that multiple and performance. A lot of press had to eat crow at the end of that run.

Beyond the surfeit of kiddie fare, there will be some adult choices this holiday weekend. Dramas entering limited release include the Weinstein Company's My Week With Marilyn, which will start out in 12 markets Wednesday, expanding to 57 Friday. Weinstein's The Artist debuts in four arthouse locations.

Sony Classics' David Cronenberg thriller A Dangerous Method will also start out in four theaters, and Millennium Entertainment crime drama Rampart will debut in limited release, too.

And for those who didn't sleep in line to see it last weekend, there's also Summit Entertainment's Twilight Saga: Breaking Dawn - Part 1, which debuted to $138.1 million.

But PG-rated films will rule the box office/

As of late Tuesday, Disney's Muppets had a conspicuously good 100 percent score on reviews aggregation site Rotten Tomatoes, with all 53 critics tallied saying nice things.

Opening at 3,440 locations, Disney is expecting The Muppets to take in somewhere in the high $30 million-range for the five-day holiday period, although outside box-office watchers figure it could take in as much as $45 million.

The movie, which cost about $45 million to make, stars Jason Segel and Amy Adams, and is about the popular puppets reuniting to save their old theater from a greedy oil tycoon.

James Bobin, of The Flight of the Conchords and Da Ali G Show, makes his feature directorial debut.

Box office watchers outside the studio say the movie is likely to perform the best of all of this weekend's opening pictures because it is a well-established brand with beloved characters and multi-generational appeal. Moviegoers who grew up watching Miss Piggy, Kermit the Frog and the other characters will find it entertaining -- and should be inclined to take their children to see it, they say.

According to research firm NRG, 88 percent of moviegoers polled are aware of the movie. The tracking is strongest among females older than 25 (i.e. a lot of moms), with 92 percent of that group expressing awareness of the movie, 37 percent reporting definite interest in seeing the film and 11 percent calling it their first choice.

Meanwhile, with its film opening up at 3,376 theaters, Sony predicts a far tougher box office climb for its $100 million Arthur Christmas, projecting a gross somewhere in the mid-to-high teens -- a projection matched by outside sources.

The animated movie directed by television director Sarah Smith answers the question, according to a studio tagline, How does Santa deliver all those presents in one night? And it also has great reviews, with Rotten Tomatoes scoring it at 93 percent.

Among its strongest demographic -- also women older than 25 -- the film is registering 63 percent total awareness, 30 percent definite interest, but only 1 percent first choice.

Finally, Paramount will debut Scorsese's first 3D family film, Hugo, in 1,277 theaters and expects to gross $10 million - $12 million over the five-day holiday.

Graham King's GK Films produced and financed the movie, which cost an estimated $150 million to make.

The movie, set in Paris in the 1930s, is about an orphan who lives in a train station and finds himself wrapped up in a mystery involving his late father, himself and a robot. It stars Ben Kingsley, Sacha Baron Cohen and Chloe Moretz. Asa Butterfield stars as the title character.