Just when you think you've seen Al Pacino milk the gangster routine for all it's worth, along comes a film like ``Donnie Brasco.''

Granted, Pacino is a great actor. There's no arguing with his brilliant performances in the ``Godfather'' films. But between them, ``Scarface'' and ``Carlito's Way,'' he's already done the brooding criminal mastermind thing to death.

But Lefty Ruggiero, the hit man character Pacino plays in ``Donnie Brasco,'' is as far from Michael Corleone (his ``Godfather'' character, for those who don't know) as he can get. Let's just say that Lefty, a chronic gambler who loses far more often than he wins, isn't going to rise to the top of the mob ladder anytime soon.

And though this fact-based film goes where dozens of dramas (and even the television series ``Wiseguys'') have gone before, it also scores some much-needed originality points by focusing on the friendship between Lefty and Donnie Brasco (Johnny Depp), a small-time hood who just happens to be Joe Pistone, an undercover FBI agent.

Under the assumed identity ``Donnie the Jeweler,'' Joe is trying to infiltrate the operations of the Bonanno crime family, who ran much of New York City in the late '70s. With Lefty's unwitting aid, he meets Sonny Black (Michael Madsen), a lesser ``lieutenant'' in the Bonanno family.

And though Sonny and his men, especially Nicky (Bruno Kirby), initially mistrust Donnie, he eventually gains their trust, especially after he sets them up with a casino deal in Florida.

But the three-year operation takes its toll on Joe/Donnie, who rarely sees his wife (Anne Heche) and three daughters. He's also torn by his loyalty to Lefty, who sees him as the son he wishes he had. (Instead, Lefty's real son is a drug addict who is continually dragging him down.)

As mentioned, aside from Pacino's lovable loser character, there are not a lot of new revelations here. Also, screenwriter Paul Attanasio's script, which adapts the real-life Pistone's autobiographical book, is more cliche-ridden than you'd expect - at least coming from the co-creator of TV's superb ``Homicide: Life on the Streets.''

Fortunately for all involved, the performances are terrific, especially Pacino. But when has he not been? But here he's even better than usual, even showing a vulnerable side that is almost heartbreaking.

Though he's not quite on par with Pacino, Depp is also quite good and manages to effectively convey the turmoil going on inside his character. And Heche is a capable match for him, though her role is much smaller. (Both even pull off the difficult accents required for their respective parts.)

The film is drastic departure for director Mike Newell, best known for the romantic comedy ``Four Weddings and a Funeral.'' But he does give things a grittier and less-than-glamorous look than you'd normally expect in a gangster film.

``Donnie Brasco'' is rated R for a continual flow of profanities, graphic violence and gore, some vulgar references, a brief sex scene, some nudity and a couple of racial epithets.