ABC, CBS and Fox all have reason to be thankful heading into the long holiday weekend.

While Fox is showing the biggest gains — due mostly to “The X Factor” — it’s CBS and ABC that perhaps have the best stories to tell this fall. Struggling NBC, meanwhile, is the only Big Four network that is down across the board.

ABC’s “Modern Family” is hotter than ever in its third season, and the net has added four shows (two dramas and two comedies) that already look like locks to return next season. CBS has bolstered its Monday comedy block with the revamped “Two and a Half Men” and the new “2 Broke Girls,” and most of its core vets are holding up nicely.

In an encouraging sign for the broadcast biz, ABC, CBS, NBC and Fox are up a combined 3% in 18-49 vs. the first nine weeks of a year ago, according to Nielsen. (The Big Four had seen year-over-year gains only two times in the prior 10 years.)

Season-to-date, CBS and Fox are tied in adults 18-49 (3.4/9), with the Eye edging up by 3% and Fox growing by a sizable 17%. They are followed by ABC (2.9/8, even), NBC (2.6/7, down 7%), Univision (1.5/4, down 6%) and CW (0.9/3, down 25%).

CBS holds a healthy edge in adults 25-54 (4.5/11 to 3.9/10 for Fox) and total viewers (13 million to 10 million for ABC).

Overall, comedy is hotter than at any other time in recent memory, and that was apparent on opening night — when Ashton Kutcher’s debut on CBS vet “Two and a Half Men” drew a whopping 28.7 million viewers. Two months into the season, the Nielsen rankers show comedies comprising 17 of the top 30 non-sports programs in adults 18-49, including four newbies.

The genre is especially dominant at the tip-top of the charts, as half-hour laffers claim the top five 18-49 spots among entertainment series — four on CBS (“Two and a Half Men,” “The Big Bang Theory,” “How I Met Your Mother” and rookie “2 Broke Girls”) and one on ABC (“Modern Family”). This hasn’t happened since the days of “Home Improvement” and “Seinfeld” in the fall of 1993.

Fox is in the rare position of leading in 18-49 even before “American Idol” hits the air. It is doing so largely thanks to “The X Factor,” which ranks 12th among nonsports series and has boosted both Wednesday and Thursday, and Tuesday comedy “New Girl,” a top-10 performer though it has slipped some after a hot start.

Among its other new shows, Fox’s dinosaur drama “Terra Nova” has underwhelmed, as has Sunday animated comedy “Allen Gregory.” And the net must have some concern about third-year skein “Glee,” down about 25% year to year.

The best news for CBS is its Monday lineup: “Two and a Half Men” has grown more than 30% year to year, and “How I Met Your Mother” is up 24%. And that has allowed the hot newbie between them at 8:30, “2 Broke Girls,” to break out as the season’s top frosh.

“Hawaii Five-0” remains solid in its second season; holding up very well are midweek vets “NCIS” (the season’s No. 1 drama in 25-54 and No. 1 series in total viewers) and “The Big Bang Theory,” which is up 15% year-to-year (perhaps due to increased exposure in syndication) and is the fall’s No. 3 series in 18-49.

Rookie dramas “Person of Interest” and “Unforgettable” are doing pretty good numbers, but two hours that could use improving are Fridays at 8, where “A Gifted Man” is doing just OK, and Sundays at 9, where “The Good Wife” has performed modestly on its new night.

ABC’s fairy-tale skein “Once Upon a Time” has emerged as the top new drama in demos. The net has also been boosted by comedies “Last Man Standing” and “Suburgatory.” The latter has fit in nicely between “The Middle” (up 17% vs. last year) and “Modern Family” (up 20% and a close second behind “Two and a Half Men” among entertainment series this fall).

And after struggling for years to find something that would work Wednesdays at 10, the net has hit on something with sudser “Revenge”; it, “Castle” and “Body of Proof” have improved the net’s overall weeknight position in the 10 o’clock hour.

The ABC misfire of the fall was “Charlie’s Angels,” while “Pan Am” hasn’t taken off like the net may have hoped but is hanging around for now.

At NBC, “Sunday Night Football” is the season’s No. 1 show and is up vs. last year, but the only Peacock program among the top 40 nonsports shows is “The Office,” down more than 15% without Steve Carell.

“The Playboy Club” was axed after three airings, and the net’s biggest rookie sparks have come from Friday drama “Grimm” and Wednesday comedy “Up All Night,” with the latter getting a time-period upgrade on Thursdays behind “The Office.”

Univision again finished ahead of CW in all key categories and was the No. 1 broadcaster in 18-49 for the November sweep in Los Angeles, Houston and Miami. The net scored big on Sunday with the finale of dancing series “Mira Quien Baila,” which averaged a 2.0/4 in adults 18-49 and 4.99 million viewers overall.

Looking at the week of Nov. 14-20, CBS benefited from an NFL overrun on Sunday to sweep in all categories, including 18-49 (2.9/8), where it held off ABC (2.7/7).

The Eye dominated the series program rankings — claiming 10 of the top 12 shows in 18-49 and 18 of the top 20 in total viewers. (This is partly due to some preemptions for series on ABC but impressive nonetheless).

It was another big week for football, as NBC’s “Sunday Night Football” (7.6/18 in 18-49, 20.31m for Eagles-Giants) and ESPN’s “Monday Night Football” (5.8/15, 14.19m for Vikings-Packers) topped the charts. Also, ABC’s college “Saturday Night Football” dominated that night (3.4/11, 9.74m for mostly USC-Oregon) and NFL Network’s Jets-Broncos game was above average (2.9/8, 7.05m).

CBS was led by “Two and a Half Men” (5.4/13, 14.77m) and “The Big Bang Theory” (5.3/15, 15.05m) and the week’s top dramas in “NCIS” (4.0/11, 20.00m) and “Criminal Minds” (3.7/9, 12.72m).

ABC’s “Modern Family” was top dog among entertainment series in 18-49 (5.6/14, 12.91m), and the net closed strongly with “The American Music Awards” on Sunday (4.3/10, 12.07m).