I can't say much more about the late Suzanne Pleshette than Ken Levine does, but there's a good website devoted to Pleshette, appropriately titled "More Than Emily Hartley, which includes a large image gallery for one of the great screen beauties of the '60s and '70s.
Pleshette probably should be on the list of "Lost Starlets of the '60s," beautiful and talented actresses who would have been movie stars in an era that offered more and better parts for women. She got a whole bunch of lead or near-lead parts from 1962 to 1965 (along with a publicity boost from her relationship with, and marriage to, Troy Donahue), culminating in a big leading part in the John O'Hara melodrama A Rage to Live. But most of those parts were in soapy melodramas, in which she didn't seem like much more than a very pretty and competent performer. It took TV to bring out her comedy abilities.
Even on The Bob Newhart Show I don't think she got used as fully as she might have been; she was, after all, not the star of the show, and her character suffered from having no regular friends or companions of her own. (The show originally had a best friend/neighbor for Emily, the "Margaret Hoover" character, but she was droppped after a few episodes.) Also it sometimes seemed to me that the show was playing down her sex appeal, dressing her unflatteringly. (Maybe to make her more plausible as a woman who would find Bob Newhart attractive, I don't know.) What she really needed was a show of her own, but CBS's attempt to give her one -- the comedy "Maggie Briggs" -- wasn't the answer.