Just another GR refugee. Other than that, I had a stroke in 2004, and read almost anything I can get my hands on, though I have a particular weakness for history, mystery, and historical fiction.
The Dark is Rising, by Susan Cooper. It's the book which gave its name to the series as a whole, and is one of the best in it.
And it is not the first book in the series - the weaker (but still fun) Over Sea, Under Stone is. If you or someone you know likes YA fantasy with Arthurian overtones (but set in the 20th century), and haven't read it, I recommend this whole series.