This is slightly different from the question that you asked,
Fordim, but there are two primarly respects in which the films have
improved my experience of LotR and Tolkien's other works.
First, while the visualisation of Middle-earth in the films largely matched the images in my own imagination, there are a number of areas where it has actually improved on them. One example which springs to mind is Theoden. I had always imagined the King of Rohan as an older man with a long snowy white beard. I much prefer the image that Bernard Hill presents, and so I have "stolen" it for my own imagination. I also always had immense difficulties imagining what Ents actually looked like. Now I have a great image, based on (although not entirely identical to) their portrayal in the films.
Secondly, I had not read
LotR for many years before the films came out. And I had never read
The Silmarillion or
Unfinished Tales. On watching the first film, I immediately went home and started reading the book. The films brought me back to the book, and to Tolkien's wider world. They also brought me to the Downs, since my first exploration of the internet in the context of Tolkien was in relation to the films, to find out who had been cast in the various roles and what they looked like. This, in turn, brought me to the Downs and ultimately (although some time later) the Discussion Forum. And that has brought to me a much wider knowledge of and broader insight into Tolkien's works than I had ever previously imagined was possible. But for the films, I might not be here (which may, in itself, be a reason for others to curse the films
).