Not including Cartoons i was wondering if anyone would have any idea what movie has the most all star cast in it?. 'The Great Escape' & 'Towering Inferno' spring to mind.
Depends on how you define a "star" but I'd agree with Tj above - the longest day is certainly a contender if you're talking major A-list stars of the time.
I think you will find that record is held by the film "The Player". I can't tell you exactly how many stars appeared in it but suffice to say it was one of the few films where actors considered it to be the 'film to be in' and accepted small cameo parts just to be in it.
I would imagine "It's A Mad, Mad, Mad, Mad World":-
http://uk.imdb.com/title/tt0057193/
It's a huge cast list and they were mostly famous when the film was made in 1963.
Although I suppose some of them were mostly known inside the US because many of them were TV stars.