Does anybody watch “Survivor: Thailand” (7 p.m., CBS) anymore? Does anybody really care? The answer to the first question is obvious: “Survivor” has been a ratings hit for CBS all season. It gives “Friends” a run for its money and consistently tops “Scrubs” for the number-one ratings spot at 7:30 p.m.

But I repeat my second question: Does anybody really care? It is difficult for even the best shows to remain a topic of water-cooler conversation season after season. While faces and places may change for “Survivor,” one gets the impression that the gimmicky challenges, tribal councils and walks into the sunset are getting very tired.

For those who do still care, “Survivor: Thailand” boils down to its final foursome in a two-hour season closer. The winner will emerge at the end of the second installment. And just in case you’ve already forgotten the names of the original contestants, the 16 stranded castaways return for “Survivor: Thailand Reunion” (9 p.m., CBS).

• A “Survivor” season finale is certainly formidable enough to drive its network competition into rerun mode. “Friends” (7 p.m., NBC) recycles an episode from last season. Or was it the season before that? Remember when Ross’s girlfriend, Mona, put his picture on her Christmas card? I didn’t either. NBC also repeats the pilot episode of “Good Morning, Miami” (8:30 p.m., NBC) as if to remind us why this is one of the more unlikeable new comedies of the year. “ER” (9 p.m., NBC) also loots its grab-bag of golden oldies, returning to Dr. Benton’s (Eriq LaSalle) farewell episode.
• It’s the sixth night before Christmas, and all though the dial, there’s not a holiday special to be found, not by a mile. OK, don’t revoke my poetic license. There is one yuletide related show on tonight, “The Life and Adventures of Santa Claus” (7 p.m., Cartoon Network), but that’s it. I will never understand why programmers start churning out Christmas programming shortly after Halloween, only to run out of gas just when everybody gets into the festive mood.

Scientists look for evidence of Christ’s crucifixion on “Quest for the True Cross” (7 p.m., Discovery). On a similarly relic-related theme, “History’s Mysteries” (7 p.m., History) discusses the authenticity of the Shroud of Turin. It’s followed by “Biblical Disasters” (8 p.m., History).

Tonight’s other highlights

• Freddie Prinze Jr. and Julia Stiles star in the 2000 romantic comedy “Down to You” (7 p.m., Fox).
• Marion must prove that she’s worthy to become the next Great Matriarch on “Dinotopia” (7 p.m., ABC).
• Scheduled on “PrimeTime” (9 p.m., ABC): An interview with Denzel Washington; a woman vanishes from a cruise ship.
• Carrie Fisher and Nigella Lawson chat on “So Graham Norton” (10 p.m., BBC America).

Series notes

Home-schooling on “Family Affair” (7 p.m., WB)…Turk’s Christmas blues on “Scrubs” (7:30 p.m., NBC)

Joel uses his knowledge of the future to suggest some surefire investments on “Do Over” (7:30 p.m., WB).

Parker Posey guest stars on “Will & Grace” (8 p.m., NBC) … Dick Clark hosts “Instant Classic Bloopers” (8 p.m., ABC) … Sixty minutes of improvisation on “Jamie Kennedy Experiment” (8 p.m., WB).

Late Night

Tom Hanks and Phish appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno welcomes Sandra Bullock, Sean Astin and the Brian Setzer Orchestra on “The Tonight Show” (10:35 p.m., NBC).

John Cusack, Jamie Kennedy and John Mayer appear on “Late Night with Conan O’Brien” (11:35 p.m., NBC) … Tori Amos is booked on “The Late, Late Show with Craig Kilborn” (11:37 p.m., CBS).