I enjoyed reading books. I thought the first few books were rather simple in terms of story and plot. As the series matured, the level of plot complexity grew. They had subplots, and this and that added depth to the books. You didn't really have that with HP-1.
The moves were a good adaptation considering the source material. However, the later movies do gloss over something in order to have a "reasonable" running time.
OP, not trying to ruin anything for you, but perhaps you will feel the same way after watching Half Blood Prince.. that movie shoudl have been made into two parts. If you read the books, which I suggest you do, you'll understand why i say Half blood Prince shoudl have been made into two films.