“Cops” (7 p.m. today, Fox), the granddaddy of all network reality series, celebrates its 20th season with an hour-long anthology of car chases, pixilated perp-walks, inebriated suspects, foot races, body tackles and Tasers.

Both grimly depressing and compelling, “Cops” has spent the past two decades following citizens too drunk, dumb or dysfunctional to obey the law. Once you brush away the tragic waste of so much repetitively clueless behavior, you can appreciate the odd Road Runner versus Coyote aspect of this unending saga.

This “Cops” commemoration arrives on the 20th anniversary of the advent of the Fox network. Actually, the first Fox shows began airing on Saturday and Sunday nights in April 1987. Every other network airs a commemorative special touting such milestones. Why not Fox?

A Fox retrospective would be a hoot. Sure, many of its early shows were embarrassing bombs, but there were gems in that compost heap. I still laugh at memories of Chris Elliott’s “Get a Life” (1990-92) and rarely missed an episode of the oddball “Alien Nation” (1989-91). “In Living Color” helped launch the careers of Jim (then James) Carrey, the Wayans brothers, Jamie Foxx, Chris Rock, David Alan Grier and Fly Girls including Jennifer Lopez. “The Ben Stiller Show” barely survived autumn 1992, but look at what Stiller has done since.

¢ On the other hand, if Fox’s handling of the recent Emmy awards was any indication, perhaps the network can’t throw a party. And I’m not talking just about the awkward “Jersey Boys” salute to “The Sopranos.” Ray Romano was censored for talking about “Back to You.” And Sally Field’s words were bleeped when she mentioned Iraq.

So now we need to be protected from dissent from the Flying Nun.

Actually, Field seemed to be channeling the grief and anger of her character Nora, the matriarch of “Brothers & Sisters” (9 p.m. Sunday, ABC), whose youngest son, Justin, has been shipped to Iraq.

The popular melodrama enters its second season with a nod to last year’s strong series pilot. It’s the first anniversary of dad’s death, and that means it’s also Kitty’s (Calista Flockhart) birthday. Worries about Justin overshadow but hardly obscure the travails of the frisky Walker family.

¢ “Dexter” (8 p.m. Sunday, Showtime) is the macabre drama about an impossibly likable serial killer (Michael C. Hall).

As the season begins, Dexter appears to be off his game but has more than mastered the art of bowling. But several developments may cast light on our hero’s dark past. Keith Carradine will join the cast as an FBI agent hot on the trail of a mystery killer.

Tonight’s highlights

¢ The documentary series “True Life” (1 p.m., MTV) returns with four new episodes.

¢ LeBron James and Kanye West host the 33rd season premiere of “Saturday Night Live” (10:30 p.m., NBC).

Sunday’s season premieres

¢ Alms in the Aloha State on “Extreme Makeover: Home Edition” (7 p.m., ABC).

¢ New neighbors on “Desperate Housewives” (8 p.m., ABC).

¢ A company-sponsored trip on “American Dad” (8:30 p.m., Fox).

Sunday’s highlights

¢ Homer sings opera on “The Simpsons” (7 p.m., Fox).

¢ Plans go awry and men die needlessly, even as victory seems inevitable on “The War” (7 p.m., PBS).