Some critics say it is an overrated movie that celebrates style over substance; the vast majority say it is the greatest movie ever made.
Citizen Kane starts with a grim image of a run down yet magnificient mansion that rather resembles a palace. In the next shot you see a dropping snowglobe and listen to the last word of a dying man that would become immortalized in cinema history: "Rosebud".
The deceased is Charles Foster Kane, a media tycoon who after the President is regarded as the second most powerful man in the USA. He owned the greatest media network in history, met the leaders of the world, built himself a gargantuan palace, almost succeeded in establishing himself as Governor and all he has to say at the end of his life is "Rosebud".
Puzzled and intrigued by this word a group of journalists, working for one of his newspapers, set out to interview all the important people and study documents which might shed some light on what Kane might have meant. The disturbing climax has not only amazed but also shocked generations of viewers.

Orson Welles' genius in this movie lies in the storytelling. You are not presented with one narrative, in fact every person interviewed, every entry in a diary paints a different picture of Kane. Starting with his childhood, turning to his first acquisition of a newspaper, women, his increasing lust for power and his slow and agonizing demise.

The character of Kane is actually based on a real person named William Randolph Hearst. In the first half of the 20th century he established himself as a media tycoon with little regard for ethics or a morally justified way of pursuing his business. Due to his exuberant and careless lifestyle he almost went bankrupt. All tabloids still work with methods developed by him. "The size of the headline sells, not the actual news!"
Welles met him once and was so disgusted by his personality and lifestyle that he decided to base a film on Hearst, although he integrated aspects of his own life as well.

Anybody who is remotely interested in studying milestones in cinema history or who would like to experience a different way of storytelling should not be disappointed by this movie. Some critics claimed that the characters come across as rather shallow and static, but they obviously failed to understand the wider context of the movie.
Most critics claim that it's the best movie ever made!