It is difficult to narrow it down to one, but Francis Ford Coppola's The Conversation feels like an extremely accurate exploration into the themes of loneliness, reticence and human detachment. Other contenders would be Buffalo '66, Detachment and Close-Up, all favourite films of mine, too.
Also, a film I recently saw, the Danish film Blind. About a woman who has recently lost her sight and retreats into the safety of her home and imagination. The film is more about loneliness and writing than blindness which is superbly realised by the director.
Possibly the topic could be made into a list since it is difficult to narrow down. – Jordan9 years ago
The title is too vague in terms of a possible objective with "loneliness/isolation" and since five different films are also mentioned and speculated over within the description, it would definitely be more appropriate for this topic to be centered around a list of some sort. – dsoumilas9 years ago
Agree with what's been said. A list of "10 great films about loneliness" or some such could be interesting though. – Winter9 years ago
Agree with the list - you've said already that it would be hard to narrow down to one. Writing it out in a list would not just help you come to a conclusion about the question AND help the reader to come to (hopefully) the same conclusion. Also, because there are so films and therefore many styles and genres that depict isolation (writing and creating itself often being pretty lonely!) you could perhaps also look into styles and genres and how that style (say, animation) portrayed lonliness/isolation. Eg, dystopian films/animation/indie films etc. Maybe making a judgement on how a certain genre depicts lonliness better than others. – Nat Parsons9 years ago