What’s new tonight:

The Big Bang Theory (CBS) 100th Episode: What a momentous occasion! BBT must have something really special in store for this episode, right? A cool, unexpected twist for all the fans? Says here, “Leonard asks Penny out to dinner.” Fascinating. ---

Archer, Unsupervised (FX) Season Premiere, Series Debut: Read all about it in True TV (Item 1).

When Girls Kill (E!) Special: E! goes all Dateline with the stories of four murderous teenage girls locked away for life — or, as they put it, “From the schoolyard to the prison yard.” Hey, at least it doesn’t involve any Kardashians.

Also new tonight:
Wipeout, Grey’s Anatomy, Private Practice (ABC); Rob, Person of Interest, The Mentalist (CBS); 30 Rock, Parks & Recreation, The Office, Up All Night, The Firm (NBC); American Idol, The Finder (Fox); The Vampire Diaries, The Secret Circle (The CW); The Real Housewives of Atlanta (Bravo); Project Runway All-Stars (Lifetime); American Stuffers (Animal Planet); Funny or Die’s Billy on the Street (Fuse); Jersey Shore (MTV)

More on that shocking, never-before-seen development on The Big Bang Theory: