Time flies when you’re being ridiculously, blissfully silly. That’s as good a lesson as any to be gained from watching Friday’s giddy hour-long tribute to SpongeBob SquarePants' 10th anniversary. Truth or Square (8/7c) attracts a rogue’s gallery of famous fans to phone in (sometimes literally) cameos saluting children of all ages’ favorite subterranean friend. The best parts, though, are pure animated SpongeBob delight.

The story, such as it is, finds our relentlessly cheerful hero and his pals celebrating the Krusty Krab’s “eleventy-seventh” anniversary, and after getting locked in a freezer—it’s that kind of show—they relive classic memories in never-before-seen flashbacks that go all the way back to the womb.

Ricky Gervais supplies a bit of twisted narration, but much of the show is framed by Tom Kenny (voice of SpongeBob) mugging his way through live-action scenes as decrepit Patchy the Pirate from Encino, who ravages the Nicktoons rolodex to corral celebs for his own SpongeBob special. Rosario Dawson, Tina Fey, Will Ferrell, LeBron James, Craig Ferguson and Robin Williams are among those playing along, but the highlights are Pink’s song about scurvy (sung in a fishbowl) and a cold call to Conan regular Triumph the Insult Comic Dog, who growls, “I don’t do basic cable. I’m on a major network. Kind of.”

As usual with SpongeBob, the jokes in cartoon or human form work on a number of levels and can be enjoyed by kids for the colorful wackiness and adults for the wry and exuberant exaggeration of it all. “This is where careers go to die,” declares Robin Williams after his encouter with Patchy. I’m not so sure. SpongeBob has done pretty well for himself so far.

The weekend’s other TV highlights are quite a bit more adult in nature. In order of broadcast:

The Wanda Sykes Show (Saturday, 11/10c): She killed in her recent HBO stand-up special. She regularly steals scenes on Curb Your Enthusiasm and The New Adventures of Old Christine. She raised more than a few hackles with her irreverent humor when she entertained in front of President Obama at the White House Correspondents dinner. Now Wanda Sykes takes on late-night comedy/talk with her own weekly series. (Read our uncensored Q&A with Sykes here.) Once that’s over, switch over to Saturday Night Live to see Taylor Swift double up as guest host and musical guest, and count the number of swipes at Kanye West.

Family Guy Presents: Seth & Alex's Almost Live Comedy Show: (Sunday, 8:30/7:30c, Fox) We really don’t know what to expect from this hybrid of variety-comedy-music-animation starring Family Guy creator Seth MacFarlane and his co-star Alex Borstein (a sketch pro from her Mad TV days). Well, that’s not entirely true. Unlike Microsoft, which bowed out of sponsorship when it realized the nature of MacFarlane’s humor, we know much of the humor will be tasteless yet probably funny. But will it seem as funny when we see the humans behind the cartoon?

Place of Execution: (Sunday, 9/8c, PBS; check local schedules) The conclusion of this gripping Masterpiece mystery, starring the marvelous Juliet Stevenson, reveals the unnerving truth behind a 40-year-old missing persons case. (For my full review of the two-part film, go here.)

Mad Men: This darkly brilliant period piece has ramped up the personal and historical drama the last few weeks, with turmoil at the ad agency, revelations that threaten to shatter for good the picture-perfect (to others) marriage of Don and Betty Draper, all of it now colored by the national tragedy of President Kennedy’s assassination. Will Sunday’s finale top all that came before, or might it feel a bit of an anti-climax? Whatever, I know I’ll be glued.