They cuss. They bicker. They cackle. That's what has made their MTV show a hit. But on New Year's Eve Ozzy and Sharon Osbourne turned unashamedly sentimental as they renewed their wedding vows in a traditional Jewish ceremony at the Beverly Hills Hotel. "The love that sparkles between you is without question the greatest gift life has to offer," the rabbi, Steven Rubin, told the teary couple, who first wed 20 years ago on a beach in Maui. Sharon, 50, frail from her ongoing chemotherapy for colon cancer but radiant in an off-white gown from Les Habitudes (accessorized with Harry Winston diamonds), elicited tender sighs of happiness from the 500 guests as she told her man, "I'm privileged to be your wife. And thank you for my babies." Ozzy, 54, dressed in somber black Armani, chimed in with a couple of hushed "I dos" during the ceremony. But when Rubin produced two glasses of wine to be sipped during the recitation of blessings, the zonky old rocker snapped back to life.

"Is this real wine?" asked Oz, jokingly alluding to his notorious history of substance abuse.

"Yes, it is," the rabbi answered. "Hold it away from your clothes."

After that, the festivities spread into two ballrooms crammed with relatives and friends including Justin Timberlake, Chris Rock, Jon Lovitz, Sharon's father (British music agent Don Arden), her doctors and her children: maids of honor Aimee, 19, and Kelly, 18, and best man Jack, 17. Guests gobbled lamb chops, sushi, Chinese dumplings and fish and chips, played blackjack and roulette and, armed with a make-believe "credit card," picked up goodies—from Godiva chocolates to Saks Fifth Avenue luxury items—at a mock mall.

The high, or low, point came at 10 p.m., when shock rocker Marilyn Manson's girlfriend, burlesque performer Dita Von Teese, did a striptease. Ozzy playfully swatted her rear, and Sharon roared with laughter.

Start to finish, the event covered the emotional spectrum. "It's all so beautiful," family nanny Melinda Varga said of the night, "and so fun."