It's a role that has won him an Emmy and made him a star on screen - and off.
"It's very weird that people know you as you walk down the street," he says.
"[Moltisanti] is a criminal who does these terrible things, that's the given circumstances, but within that they see someone who struggles with themselves, you know? And trying to live a life with friends, with coworkers, and a love interest, and trying to do the best they can with that. And trying to live a noble life... I think people can relate to that."
Most reviewers agree the success of Tony Soprano - played by James Gandolfini - and other performers on "The Sopranos" stems from the fact that their characters are complex, alternating between evil and suburban banality without conscience - yet haunted.
"It's fun letting out that shadow, that dark side that we all have as human beings, but we try to keep it in check most of the time," says Imperioli.
Michael Imperioli was born 38 years ago in suburban New York. Except for playing Oliver Twist in 4th grade, he never mentioned acting to his parents again until the night before he was supposed to leave for college.
"I was like, 'You know what? I don't think I'm going to go,'" he says. "I wanted to be in this city and I wanted to go to acting school... And they were like 'Well you know, it's your life. If that's what you want to do. As long as you're really serious about it.'"
Friends from the neighborhood never doubted he'd make it, and say success hasn't gone to his head.
Imperioli worked as a waiter, a role played by many a struggling actor. "Waiter, bartender, busboy, cook, you know whatever…I also moved furniture. I was a messenger. I did phone market research, that was probably the worst job."
In between jobs were bit parts in movies. He's been in more than 40, including "Goodfellas", "Clockers", "I Shot Andy Warhol" and "The Basketball Diaries".
As a running gag, he has Christopher struggling to write a screenplay about the mob.
Imperioli has written screenplays, too, with credits like "Summer of Sam" and five episodes of "The Sopranos".
"I find it a lot harder, probably because acting is what I've really done, mostly," says Imperioli. "Writing is a blank page, you have to fill. It's a solitary thing."
Last year, Imperioli opened a small theater in New York he calls Studio Dante. It is in a dilapidated brownstone, and the construction and decorating were done by his wife, Victoria.
Colleagues from "The Sopranos" work on projects with him.
The cast is riding high right now. Last Sunday, "The Sopranos" won the Emmy for best drama series.
But along with the accolades, there are still the critics. Imperioli says it bothers him that a number of Italian Americans think "The Sopranos" is stereotypical.
"It's like Italian Americans have assimilated enough into our culture to the point where 'The Sopranos' is not going to keep some kid who's Italian American from getting into a good college because the dean thinks his father is a mobster because he happens to be Italian. I mean we're past that, you know."
"The Sopranos" is on hiatus. Its next season, said to be the last, won't air until 2006. One character who won't be there anymore is Christopher's girlfriend, Adrianne. She was killed off for working with the feds.
He says he doesn't know when the next character is going to get whacked.
"We don't know… we know as a group a couple of weeks before. We have a tradition when someone is going to go, we take them out to dinner. So when you get asked to go to dinner, it's not a great thing."
During time off from "The Sopranos", Imperioli pursues passions like tae kwon do and playing the horses. He's also shooting some outside projects including a first: the voice of a cartoon character, Frankie, in "Shark Tale."
"It's challenging... to have to communicate a character just with your voice, without, you know, your eyes or your gestures or anything like that," Imperioli says. "I finally did something my children can actually see."
"They say, 'My father's a shark, that's what he does for a living.'"