I don't remember the first two films but I must have seen them when the trilogy was shown on UK television in the 70s. The one that stuck with me, in fact terrified me, was the third one of the trilogy, Amelia. It's come up now to my mind from an article in the Guardian and I would never have known the name of it unless I'd read that article.
I was watching at my parents' house after they had gone to bed. I honestly didn't know what I was letting myself in for. That doll made me genuinely frightened. Whoever, in the props department, conceived of it was an evil genius. The way it moved, chasing its victim through her flat was perfect, as was the terrible noise it made.
I met some friends the next day who shared a flat. They had also watched the film and afterwards all slept in the same bedroom together as they had been so freaked out. I'm glad I hadn't been the only one to have been utterly spooked. I admit that when I went to bed, I was worried that that horrifying doll would come charging out from under a cupboard or out of a wardrobe.
I can still feel the frisson of terror forty five years later. It's one that I shall never forget.