NEW YORK -- "My cankers," answered Julian McMahon.

"My eight toes," replied Dylan Walsh.

The stars of the hit FX drama "Nip-Tuck" were responding to the statement they, as tag-team plastic surgeons, pose to their clients: "Tell me what you don't like about yourself."

McMahon and Walsh were kidding, of course. Just as they were kidding when a reporter asked a follow-up question: Whether either actor has submitted to a real plastic surgeon's nip or tuck.

"There's NOTHING I haven't had done," joked McMahon, who portrays the rakish Dr. Christian Troy.

"Not yet," declared Walsh, the series' stumbling family man, Dr. Sean McNamara. "But after the second season," he added wearily, "I might need a little bit of work."

There's plenty of playful banter from these guys as they celebrate their show's triumphant first year. But on the season finale (9 p.m. Tuesday), like the 12 episodes that preceded it, "Nip-Tuck" doesn't play around, even when it's riotously funny.

For the audience, "Nip-Tuck" draws blood with its all-too-graphic surgery scenes. The rest of the time, it slices even deeper into personal issues like love, sex, beauty, aging and the vagaries of male friendship.

As it bridges the gap between outer appearance and underlying truth, "Nip-Tuck" may sometimes make viewers cringe. But they can't turn away. Averaging 3.3 million viewers, "Nip-Tuck" is this year's top-rated new series on basic cable (making it a worthy companion to FX's sophomore hit "The Shield").

The first season ends on a cheery note, a neat trick inasmuch as one or both of our heroes have been coping with a murderous drug lord, life-threatening extortion, accidental fatherhood, infidelity, a lover's death, a sleazy rival to their high-end Miami practice -- plus lots of inner doubt.

"Is this where you thought we'd be at 40, Christian?" moans a distraught Sean. "Further behind and more confused than we were at 24?"

Poor Sean.

"My character has everything he ever wanted," says Walsh, whose past work includes a recurring role on "Everwood" and the film "Nobody's Fool" with Paul Newman. "Sean got the girl he wanted" -- wife Julia, played by Joely Richardson -- "the kids, the practice, the house, the money. And he's miserable. That's what I like."

And what of Christian? Here's a binge womanizer who may even be the father of Sean's high-school-age son.

"This is a constant challenge," McMahon said, "to be playing a character who is -- I don't know any other word for it -- out of control."

The Australian-born McMahon, formerly a star of the series "Profiler" and "Charmed," marvels at Christian's appetites and the lengths he goes to satisfy them.

"He blows me away when I pick up the script and read what I get to do," said McMahon. "I'm so in love with being able to play this guy."

Even away from the show the stars can't quite get outside their roles.

"Sometimes I look at somebody and think, 'She could use a little lift,"' Walsh confessed. "It becomes part of your subconscious when you're dealing with it every day."