There are all kinds of reasons we sit down to watch movies. Often we're looking for something fresh and exciting we haven't seen before; sometimes we revisit that which we've seen previously in the hopes of some new insight.
However, there are also times when all we want is to kick back with something we've seen time and again, yet never grow tired of.
This, surely, is the key reason the video/DVD/Blu-ray market exists: the joys of repeat viewing, watching movies over and over until, by accident or design, most of the dialogue and action is committed to memory. Yet even then, further viewings often bring to light little details you didn't quite pick up on before, which only enhance your enjoyment that bit further.
Obviously, opinions are going to vary on the subject, and most of us (this writer included) will have certain favourite movies that mean a great deal to them personally, even if they're not so widely adored.
However, it's fair to assume that most if not all of the following 15 films will be on the shelf of any real movie lover; and that the films in question will have been played, and replayed, and replayed a great many times over the years, with a great many more viewings sure to come in the future.