"The Ring" is a decent Americanized verison of the Japanese horror film "Ringu". While it removes things that American audiences may have trouble understanding or accepting (i.e. the boy's father is somewhat psychic, and this is never addressed as being odd), it adds some interesting twists and features (i.e. the horses). While both films end the same, I find the Japanese version to be creepier - possibly because I saw it first.
If you're into Japanese films, get "Ringu". Otherwise, "The Ring" is a decent scary filck.