After a quick four seasons, “The O.C.” (8 p.m., Fox) airs its final episode tonight. I do not pretend that I have faithfully followed every nuance of the show since its debut in late summer 2003, when it quickly became a pop culture phenomenon. I was not shocked that Marissa Cooper was killed off last season – only that she didn’t succumb to starvation.

Few shows inspire a line of Christmas, or make that Chrismukkah, cards or generate as much cannibalizing cable competition (“Laguna Beach: The Real Orange County” and “The Real Housewives of Orange County”).

Whatever one thought of the teen soap shenanigans on “The O.C.,” the casting was strong, and the young leads, Mischa Barton, Benjamin McKenzie and Adam Brody, were endowed with star power. The contrast between Ryan (McKenzie), the strong, silent type from the wrong side of the freeway, and Seth (Brody), the pop-culture-saturated chatterbox, was a natural.

And it was always fun to watch Peter Gallagher as bleeding-heart lawyer Sandy Cohen.

With rare exceptions, I am never happy to see a show canceled. But there is something about the fast and furious trajectory of “The O.C.” that may make it more memorable than the average network series. Many shows, even the best, outlive their greatness and outlast their audiences. Shows like “That ’70s Show,” “Malcolm in the Middle” and even “Seinfeld” come to mind.

In contrast, “The O.C.” will vanish after a season that many in its dwindling cadre of fans consider a vast improvement over the previous one. No show lasts forever, and few shows could survive competition from “Grey’s Anatomy” and “CSI.”

“The O.C.” will not be soon forgotten. Particularly since it begins a five-night-a-week round of syndication on Soap Net, beginning April 9. And there are always DVDs. Also on tap for t:

– Former Oscar winners Julia Roberts, George Clooney, Nicole Kidman, Russell Crowe, Jamie Foxx and Sidney Poitier appear on “The Oprah Winfrey Oscar Special” (9 p.m., ABC). Oscar purists need not worry: The Barbara Walters special will air on Oscar night (Sunday) as it has in years past.

– Filmmaker Rory Kennedy interviews soldiers, prisoners and experts on torture in the film “Ghosts of Abu Ghraib” (8:30 p.m., HBO). She tries to understand the policies and atmosphere that contributed to the use of torture and explores how the incidents and images from the prison have come to define the United States in the minds of the very people our government wants to liberate or at least make sympathetic to us.

Tonight’s other highlights

¢ Two men and two women face the ax on the results show of “American Idol” (7 p.m., Fox).

¢ On “Grey’s Anatomy” (8 p.m., ABC) a fight for life.

¢ Michael and Jan go public with their furtive affair on “The Office” (7:30 p.m.).

¢ A basketball star and his cheerleader girlfriend go missing on “CSI: Crime Scene Investigation” (8 p.m., CBS).