What's Worth Watching:The Big Bang Theory, The Voice, Gotham, Lucifer, The Good Place and more for Monday, September 19.

Matt Roush
The Big Bang Theory
Monty Brinton/Warner Bros. Entertainment Inc

The Big Bang Theory (8/7c, CBS): Still on his journey to understand what makes these curious things called humans tick, Sheldon (Jim Parsons) asks, "Why do people cry at weddings?" Witnessing Leonard (Johnny Galecki) and Penny (Kaley Cuoco) renew their vows, Sheldon's mother Mary (Laurie Metcalf) chimes in: "They're practicing for what's coming later." Big Bang's still got it, 10 years into its run, and gathers one of its starriest guest casts for the occasion. Returning are the peerless Metcalf and Christine Baranski as Leonard's icy mother, Beverly, who's none too pleased at the implication that her ex-husband, Alfred (Judd Hirsch) may be getting way too cozy with "bible-toting bumpkin" Mary. Into this awkward mess arrives Penny's family: dad Wyatt (Keith Carradine), insecure mom Susan (Katey Sagal, who once played Cuoco's mom on 8 Simple Rules) and jailbird brother Randall (30 Rock's Jack McBrayer). It's a pretty classy and hilarious way to kick off the new season, airing through late October on Mondays while Thursday Night Football takes up residence on CBS.

The Voice (8/7c, NBC): The blind auditions are an irresistible hook that makes the first part of any Voice season sing, and the hype is even heavier with two new female couches—sassy Miley Cyrus and soulful Alicia Keys—taking chairs alongside Adam Levine and Blake Shelton.

Gotham and Lucifer (8/7c and 9/8c, Fox): Fox kicks off its premiere week with the third and second season premieres, respectively, of two decidedly ghoulish series. Gotham is besieged by monsters, with Jim Gordon (Ben McKenzie) as bounty hunter, while Bruce's (David Mazouz) doppelganger runs loose. And Lucifer's (Tom Ellis) mother (Tricia Helfer) is the new thorn in the devil's side, after escaping from Hell and causing a distraction in his and Amenadiel's (DB Woodside) search for the missing Maze (Lesley-Ann Brandt).

The Good Place (10/9, NBC): Premiering with back-to-back episodes before moving to Thursdays later this week, this offbeat fantasy-comedy is original, to say the least, as Kristen Bell awakens in Heaven, wondering what a bad girl like her is doing there. It's a case of mistaken identity, clearly, but the repercussions are epic, much to the consternation of her guide to the afterlife, played by a charmingly chipper Ted Danson.

Inside Monday TV: The documentary to watch is HBO's Three Days of Terror: The Charlie Hebdo Attacks (8/7c), reliving the horrors of the January 2015 massacre and the ensuing manhunt that involved yet more attacks throughout Paris, by assailants claiming allegiance to ISIS. … Or you could witness more speculation in the two-hour conclusion of The Case of: JonBenét Ramsey (9/8c). … A new season of National Geographic Channel's wide-ranging StarTalk with Neil deGrasse Tyson kicks off (11/10c) with Whoopi Goldberg as guest. … Just days after Donald Trump's appearance kicked off a firestorm of criticism, NBC's The Tonight Show With Jimmy Fallon (11:35/10:35c) gives equal time to Hillary Clinton. Will he insist on messing with her hair, too?