The question was not unreasonable in the circumstances. "What," I demanded of Matthew Cole, "is your number one film?" He is, after all, the producer and director of The 100 Greatest Films, which occupies six hours of primetime viewing at the weekend. But after nine months of living and breathing movies, he's suffering from celluloid overload.

So it was difficult to decide between Brando's offer he couldn't refuse in The Godfather, Bogart asking Sam to play it again in Casablanca, or Luke Skywalker getting life lessons from Yoda in the Star Wars adventures.

"It's a tough one because my attitude to films has changed in making this programme," explains Cole. "My own top 100 has altered during the making. I don't really know what's number one. If I had to answer now I would probably say Apocalypse Now or The Godfather. It changes from minute to minute. If you ask anyone what their favourite film is, it's going to be different from one day to another."

I can sympathise with him. The inevitable question asked of anyone who watches and reviews films professionally is "what's your favourite film?". I find it as impossible as Cole to answer. Unlike paying cinemagoers, critics don't choose what to see. They are force fed movies of all descriptions, shapes, sizes and languages. It's simply a case of liking some more than others.

The 100 Greatest Films isn't concerned with Cole's preferences, or mine. Which is probably why the list is what he describes as "broad-ranging" and others might call downright bizarre. French art house movies such as Jean-Luc Godard's Au Bout De Souffle nestle alongside Julie Andrews singing about her favourite things in The Sound Of Music. Fred and Ginger trip the light fantastic in Top Hat as Olivier's Henry V goes once more into the breach, dear friends.

Films from the early days of cinema, including Eisenstein's 1925 The Battleship Potemkin and the 1935 Bride Of Frankenstein, are in competition with more recent offerings such as Gladiator with Russell Crowe. Bruce Lee's martial arts thriller Enter The Dragon is engaged in a duel with the Oscar-winning Crouching Tiger, Hidden Dragon.

The list contains the expected - such as It's A Wonderful Life, Casablanca, Star Wars, Gone With The Wind, ET - and the unexpected, led by Jean De Florette/Manon des Sources and Three Colours Trilogy. The long-running James Bond franchise is represented by Goldfinger. Saturday Night Fever earns a place but not another, equally-popular John Travolta musical Grease. Speilberg's ET, Jaws and Schindler's List are there but none of the Indiana Jones adventures. Alfred Hitchcock is represented by Psycho and Vertigo rather than North By Northwest, which many would regard as superior to both.

North-East born director Ridley Scott represents the region with no less than three nominations, for Alien, Blade Runner and Gladiator. And Mike Hidges' 1971 Newcastle-set gangster thriller Get Carter, starring Michael Caine, is in the list too. No mention, though, of Billy Elliot, one of the most successful British films of recent years, which starred Billingham schoolboy Jamie Bell.

You get the picture from that snapshot of the final 100 that the Channel 4 list is probably quirkier and more unpredictable than most other movie lists. Anyway, greatest doesn't necessarily mean favourite. We all have films we can watch time and time again for sheer enjoyment but wouldn't claim they were great films or had any particular merit above an ability to entertain. Even really bad films - the Joan Crawford daughter-beating drama Mommie Dearest springs to mind - are so bad they are good to watch. Gone are the days when Orson Welles's Citizen Kane regularly topped the poll. Cinema audiences are more youthful now, something reflected in the latest polls where Titanic is just as likely to take the top spot. It's not the greatest film ever made by any stretch of the imagination but, as the highest-grossing film of all-time, is the one seen by more people than any other. By that measure, expect to see the box office champ Harry Potter And The Philosopher's Stone feature in future lists.

The choice also reflects Cole's desire to avoid compiling a movie buff's list. He's making a piece of popular television, not a visual thesis on the art of cinema. The 100 films are basically a poll of polls. Cole and his team collected seven or eight greatest lists from the past few years and found the "golden 300" that cropped up in all of them. "Then we went to our panel of writers, directors and critics to vote on them. We came up very easily with 130, but had more difficulty narrowing it down to 100. People could vote for that list on the Channel 4 website," he says.

"What's different about this list is that it's probably the most broad-based list that's ever been compiled, representing so many different genres and periods of film-making. That's one of the most exciting things about it - to have a modern British comedy like The Full Monty alongside Belle de Jour and The Battleship Potemkin. "Even if the films are ones people haven't heard of, they will have felt their influence. They're films that still have a relevance today. It's not purely a film experts list."

Cole, who calls himself a cinemagoer not a movie buff, admits some people will be surprised by the omissions. He points out that, on the website, people had the option to nominate films not on the official list but no strong candidates for inclusion emerged. "There were no clear leaders, no films crying out to be included," he adds.

The list was intriguing enough to persuade top film-makers and actors to be interviewed for the programme. Steven Spielberg, Quentin Tarantino, Ridley Scott, Mike Leigh, Michael Caine, Sigourney Weaver, Richard Attenborough, Robert Duvall and Omar Sharif are among those appearing.

"Most of them were encouraged to talk to us because they were impressed by the range of the list. It's different to the lists in the States," says Cole. "William Friedkin, the director of The Exorcist, said that, in America, the list would be 100 American movies. With our list, the directors could see there were more interesting European films for them to talk about, films that weren't made in Hollywood."

Now he's sitting back and waiting for the arguments that will surely follow when the countdown is revealed in two programmes, presented by Graham Norton. "Part of the joy is the controversy it will cause. It's not a science but you have a good go at making the most enjoyable and most relevant list you can," says Cole.

* The 100 Greatest Movies is on Channel 4 on Saturday and Sunday at 9pm.

* The Northern Echo has listed the films on-line so that you can vote for your top three favourites. One entrant will win a £20 voucher for the V Shop at the Cornmill Centre, Darlington. Visit: filmvot