Watch it

“Onion News Network” (7 and 11:05 p.m., IFC). Breaking news: A sex scandal between a conservative senator and a horse.

“Portlandia” (7:30 and 11:35 p.m., IFC). Singer/songwriter Aimee Mann guest-stars as Fred and Carrie’s maid. And other weird, hipster things happen.

“Who Do You Think You Are?” (8 p.m., NBC). Season premiere. The celebrity genealogy series is back for a second season. Tonight’s episode features actress Vanessa Williams, who traces her family back to Civil War-era South Carolina. It’s a mildly interesting series, certainly better than any other of NBC’s reality programs.

“Fringe” (9 p.m. Fox). The team investigates a mysterious blue powder that makes bones disintegrate. Not surprisingly, Walter’s past may have something to do with its origins.

“Spartacus: Gods of the Arena” (10 p.m., Starz). Batiatus’ plan to become a big-shot gladiator owner are going swimmingly, until his father returns to town. And uh oh, he’s upset to find his favorite gladiator trainer slain. I admit, I’m getting hooked. Tonight the official Vegas line puts the over/under on gratuitous sex scenes and slit throats at five. I’m betting the over.

Record it

Just a nerd alert FYI, “Smallville” (8 p.m.) and “Supernatural” (9 p.m.) are back with new episodes tonight on The CW. They were originally scheduled to debut last week, but got bumped due to the State of the Union.

“Law & Order UK” (9 p.m., BBC America). A cop’s suicide is linked to a pedophile ex-priest. Geez, another episode about horrific crimes against children. What is it about this series? It’s almost darker than “SVU.”

“Ricky Gervais Show” (9 p.m., HBO). Tonight’s topics include Karl’s thoughts about mimes and the wisdom of celebrating birthdays.

Skip it

“Super Bowl’s Greatest Commercials” (9 p.m., CBS). Dude, you’re getting suckered into watching an hour’s worth of commercials that you’ve already seen.