Metalheads

A lot of British sitcoms are designed to make viewers squirm on their couches. "Detectorists," now in its third and last season, is different. Creator Mackenzie Crook and Toby Jones play lovable losers hoping to strike gold through metal detectors and sheer stubbornness. If you're looking for buried treasure, start digging here.

Now streaming on Acorn TV

Wanna be startin' something

"Lip Sync Battle" goes live with a tribute to Michael Jackson featuring Cirque du Soleil. LL Cool J, a recent recipient at the Kennedy Center Honors, returns as host alongside Chrissy Teigen. The fourth season officially returns Jan. 25.

8 p.m., Spike TV

There goes the neighborhood

It's the final season of "Portlandia," the collaboration between Fred Armisen and Carrie Brownstein that created skits more subtle and sympathetic than anything you'll see on "Saturday Night Live." The duo continues to present Portland as a West Coast version of Minneapolis, which means their characters will drive you crazy and win your heart.

9 p.m., IFC

Neal Justin