Anybody wondering why critics lament the current state of sitcoms need only look at this television groundbreaker for proof that delicate, humane storytelling goes a lot further than crass, lowbrow humor. The crown jewel of CBS’ Saturday lineup for most of the ’70s dug deeper — and grew more urbane — in The Mary Tyler Moore Show: The Complete Second Season, tackling workplace ennui, marital discord, the unfortunate strains found in the best of friendships, and even anti-Semitism (in a classic episode starring future Newhart regular Mary Frann as a bigoted WASP). The peerless Nancy Walker also makes her first of many hilarious appearances as Rhoda Morgenstern’s incorrigible ma, Ida?a sort of early prototype for The Golden Girls’ raucous Sophia Petrillo. EXTRAS Three episodes feature lively commentary tracks (Edward Asner, for instance, admits that he was just as misogynistic as his alter ego Lou Grant when he came on board), and a documentary dissects each of the show’s eight main characters with fresh interviews. There’s also a karaoke version of the theme song, clips from the 1972 Emmy Awards (a tearful, unglam Valerie Harper ties with All in the Family‘s Sally Struthers — and they accept together), and ”Moore on Sunday,” a news show featuring outtakes of Mary strolling the actual Minneapolis streets as she filmed the show’s updated opening credits sequence.