Malcolm McDowell may forever be remembered as Alex DeLarge, the psychopathic punk rapist and murderer in Stanley Kubrick's "A Clockwork Orange," but in the eyes of his 18-year-old son, "Gangster No.1" is his coolest movie -- for the moment.

The young film buff, who has seen quite a few of his father's 100-plus films and TV shows, gave the following ringing endorsement after watching the flick about a vicious Cockney mobster:

"Dad," he said, "this rocks!"

McDowell tells this story with an ironic, "these kids today"-type expression on his face, as if he's not sure what to make of that response. Should he be proud that his son liked his movie? Or should he be worried that his son was so enamoured of a movie about a violent, vile criminal who is perpetually seething and jealous?

Whatever the case, it's clear from talking to McDowell about the picture that he enjoyed playing the character -- a nameless, cigar-chomping, back-stabbing monster at the top of the criminal food chain. Gangster's greatest pleasure in life is that everyone he knows is scared to death of him. But his greatest fear has just come true: His old boss (played by David Thewlis, "Beseiged" "Seven Years in Tibet"), the man he tried to kill when consolidating power in his hungry and ruthlessly ambitious youth, is getting out of jail 30 years after Gangster framed him for murder.

In those 30 years, McDowell's mafia thug hasn't changed except to become more brutal and bitter. But while everyone around him is played by the same actor in the film's two time periods -- 1968 and 1999 -- the younger version of McDowell's Gangster is played by Paul Bettany (Russell Crowe's imagined roommate in "A Beautiful Mind," the wise-cracking Chaucer in "A Knight's Tale").

The two give amazingly in-sync performances -- Bettany is often acting out thoughts described in voice-over memories by McDowell -- that make the metaphorical dichotomy work to memorable effect.

Although the film was shot almost three years ago, it's still fresh in the mind of McDowell, who was recently in San Francisco for its screening at the city's International Film Festival. Clad in a denim shirt and jeans that match exactly his incredibly bright blue eyes, and a T-Shirt the same color as his extremely white hair, he makes a memorable impression even before he starts talking. When he does speak, his face becomes a roadmap of fantastically expressive lines and wrinkles that seem to conspire for maximum dramatic effect, whether it be in a warm but mischievous smile or a malignant scowl as he repeats his hateful character's lines from the film.

Q: You've played a lot of abominable bad guy roles -- scenery chompers -- whereas this role is very three-dimensional, something you can really sink your teeth into. How do you choose the parts you take?

A: This was a no-brainer because it's well written. It was a very interesting director, and the producer, Norma Heyman, I've known for years and years and years. I wanted to do it because it's a great part. You know, (my part) is from a play. The voice-over is the play. I basically do the play, and the kid, Paul Bettany, does the film. I think he only has like 10 lines.

Q: And that's reflective of the character: He thinks five times as much as he speaks.

A: Right, and I'm doing all that (in voice-over).

Q: Bettany does a great job expressing non-verbally what you're saying (in the voice-over). Did the two of you get together to work that out?

A: No. Nope. He was invited onto the set for the first week. I was working, and I did a big scene with David Thewlis in that apartment at the end (in which Gangster confronts the returning mob boss). He was around for all that (watching me). After it I had to leave -- I was doing another film -- and I said, "Paul, it's up to you now. Don't f**k it up." And I just left. [Laughs]

Q: So Bettany watched you play the character at his most intense, then picked it up from there, taking the Gangster backward to an earlier time in his life.

A: Yep. He did. He's smart, he's a good actor, and I think he's awful good in (the role).

Q: Other than getting angrier and more entrenched, your character changes the least psychologically in the course of 30 years. But obviously he changes the most physically because he's played by two different actors. It's an interesting juxtaposition.

A: The amazing thing is, Paul Bettany is six-foot-four! [Laughs] (McDowell is 5'10") But he looked at "Clockwork Orange" and a few other films from when I was his age, and he really got the look. I don't think that you really question the fact that we're different people.

Q: You and he didn't have to go through the age makeup that the other actors did. But it's incredibly well done. David Thewlis -- who is what? 40? --plays 29 and looks great, and he plays 50-something and looks great.

A: Yes, it was unbelievable. So get this -- this is funny: I'm in makeup with him one day, (while) he's doing his makeup for the old guy. So there he is [pantomimes the application of Latex face accoutrements], and I'm doing mine [pantomimes a quick powder-puffing] -- and right! I go off and do a six page scene -- a six minute monologue, which was cut from the film. I'm literally out on the stage all day. I come back, I sit down, I look over, and there's Thewlis! I went, "F**king hell! Are you still doing your old man makeup?" It was hilarious. But he's a very good actor.

Q: Is it fun to do a scene like the one where Gangster and Freddie Mays (Thewlis) finally meet again after 30 years and Gangster just blows up trying to figure out why the guy isn't mad (about being framed, jailed and robbed of his empire)?

A: Oh yeah. It's fun because there's so many strings to pull.

Q: He thought becoming the kingpin would fulfill him, and it didn't at all.

A: Exactly. Exactly. And he's jealous of this Freddie Mays. He's obsessed with Freddie Mays, with this guy who has gone into prison, gotten a Bachelor of Arts degree, stopped drinking, stopped smoking...

Q: ...and his girlfriend waited for him!

A: Yeah. Yeah. He's become a real person. A moral person. And Gangster finds this abhorrent. He just can't fathom it, and it pisses him off. That's what drives him nuts.

Q: It seems to me that most of your roles you take because they're fun to play as an actor.

A: Well, I like to think that I bring that to a role. I don't think the roles say "Hey this is going to be fun!"

Q: I can see that. I didn't think much of "Just Visiting," but you were the best thing in it because you make your role fun. (He played a medieval wizard who spends the movie looking for time-traveling knights in modern day).

A: "Just Visiting?" What's that?

Q: The French knights in Chicago. They changed the title from "The Visitors."

A: Oh, oh! Right. Isn't that funny? I was filming "Gangster" and that (at the same time). I was running from one set to the other. I'd finish one day beatin' the crap out of Thewlis [laughs], then the next morning the car would come to drive me to Sheparton to do this Medieval thing! What really threw me was when I suddenly saw the same stand-in I had for "Gangster" appear there. I started going into "Gangster" mode, talking like "What the f**k are you doing here?"

Q: You work so much, I wonder how much time you actually get off. Do you do small roles so you're working, say, three weeks at a time?

A: I like that. I like that because then I can get home, spend a month, then go and do another project. They (the filmmakers) have to shove it all into one (time period). If I have to hang around, forget it. The English have no idea how to draw up a (schedule). I get a lot of "We want you for 16 days, but it's over 12 weeks." I go, "12 weeks? Are you nuts?" I'm so used to working in America, where they're efficient!

Q: So what's next?

A: I'm on my way in a few weeks to work on my daughter's 16mm senior project for film school. I'm getting all sorts of directions from her right now, which is irritating me beyond belief. Things like, "Don't shave." I'm doing a movie with Eddie Murphy at the moment! What do you mean don't shave?!? "They're paying me," I told her. "You're not!"