'Lassie Come Home' is excellent, well and tastefully told, with good acting. The death of the small dog, Toots, is heartbreaking, of course, and could be skipped if a parent felt it necessary. However, I think it is well-handled. My grandchildren seem okay with it. We watch this film over and over. I highly recommend it. I believe Lassie is in just about every scene, if not every scene. It is a wonderful film and beautifully done.
On the other hand, the other two films are disappointing. The acting in 'Son of Lassie' seems amateurish.
As for 'Courage of Lassie', in spite of the beautiful opening scenes and a fascinating story line, the war scenes of the dog leading the men are gruelling. For dog lovers, the cruelty to the dog during these scenes is too much to watch. I myself was in tears throughout. I would not show it to my grandchildren.