From The Andy Griffith Show's bumbling Barney Fife to Three's Company's Mr. Furley, the googly-eyed actor proved to be one of TV's most endearing sidekicks

Long after they teamed up on The Andy Griffith Show, the classic '60s sitcom in which Griffith starred as Andy Taylor, the laid-back sheriff of fictional Mayberry, N.C., and Don Knotts played his jittery, high-maintenance deputy, Barney Fife, the two men remained close friends. "They would talk on the phone for hours and share the deepest confidences," says Knotts's third wife, Francey Yarborough.

So it was only fitting that Griffith, 79, was at his old pal's bedside on Feb. 24, just a few hours before Knotts succumbed at 81 to complications from lung cancer in an L.A. hospital. "I told him I loved him and I held his hand," says Griffith. "I said, 'You gotta breathe, Jess!' Jesse was his [real] first name. 'You gotta whip this thing.'" Though Knotts was unconscious, "his chest heaved several times, and I believe he heard my voice."

The real Don Knotts was nothing like blustery Barney, says Griffith, who first met the onetime ventriloquist from Morgantown, W.Va., when they were castmates on Broadway (and later onscreen) in the comedy No Time for Sergeants. "He was modest, he was humble and he was very bright," says Griffith. Adds director Ron Howard, who played Andy's son Opie: "He was just one of those truly kind people, very unassuming and very respectful."

"The reason I'm in the business is because of Don," says another pal, Tim Conway, The Carol Burnett Show veteran who performed with him on The Steve Allen Show and teamed with him in five movies from 1975 to 1980. "He was the Charlie Chaplin of our era. He left us with a wonderful, gentle character who can never be duplicated."

But there was another side to Knotts. "Dad was kind of wild," says Karen Knotts, his actress daughter by first wife Kathryn Metz, with whom he also had a son, Thomas, now an electrical engineer. "He was really quite a ladies' man, especially between marriages."

In that respect, he was not unlike landlord Ralph Furley, the leisure-suited wannabe swinger he would go on to play on Three's Company. On the set, "he'd put down the script and just become this physical force you couldn't help but laugh at," says costar Joyce DeWitt, who remembers Knotts and the late John Ritter doing dueling Jack Benny impressions off-camera.

Late in his career, Knotts would tour in Harvey and other stage revivals, joined by Yarborough, 43, who fell in love with him 20 years ago and married him in 2002. Diagnosed with lung cancer last November, Knotts, who'd quit smoking decades ago, "was upbeat and getting chemo," she says. "But he didn't even tell his own children. He figured he'd beat it and go on with his life." At his deathbed, says Karen, "I found myself telling him everything I wanted to say before he left. He was listening. I know it. I could feel it."