The old 1946 Cineguild production of Great Expectations with John Mills and Valerie Hobson is much shorter than the BBC miniseries, it is true. However, it works well when the teacher does not have as much time as is necessary for viewing the BBC film. Also, if there are some reluctant readers or readers who are not on grade level ability, this old movie has a great Miss Havisham and the students enjoy her character. Interest in the novel is often, then, generated as students can more easily imagine the characters and "hear" them in their minds. The old film is available from Turner Classic Movies. In fact, it was on the TCM channel just a couple of weeks ago.
Though there are countless media adaptions of Charles Dickens's Great Expectations, I've found that the BBC's 1989 miniseries is the adaptation that is most true to the novel. Though this miniseries is divided into "Chapters" that aren't numbered according to those in the novel (instead, they were composed to fit the three 2-hour time slots in which the miniseries originally aired), there is very little that is left out of this film (it's over 300 minutes). Anthony Hopkins plays Abel Magwitch, and Jean Simmons, who played Estella in a previous film, plays Miss Havisham.
Though I don't show the entire film because of issues with time, I find that this film is the best when it comes to showing excerpts after reading particular sections. It is painstakingly complete, with regard to the novel's content, so teachers have the luxury of showing just about any scene they feel is important.
I tell my students that because the most important passages in the novel are those of Pip's narration, no film (unless it has a narrator to read these passages, which the BBC series doesn't) can truly capture the brilliance of this novel--not even one that's 300 minutes long and includes virtually every episode in the novel.