Wow, its been awhile...in retrospect my initial comment would be that Ringu is far more creepy and unsettling than The Ring by a mile. Not to mention that Sadako would make Samara her bitch any day of the week.
Ringu has much more of a film noir quality not to mention the lower budget which definitely affected Hideo's approach and made for a more disturbing aesthetic. I also liked the more murky spiritual backstory in reference to Sadako's mother mating with some being from the sea.
Its a given that Verbinski had to produce a different feel for the american audience and obviously had the resources for a major upgrade. But all in all Verbinski stayed true to the story and foreboding atmosphere, I actually enjoyed The Ring very much, but in a versus match between the two my money is on Ringu.
on a side note I was really disappointed with the adaptations of Dark Water and Ju-on, so I'm a little skeptical about future J-horror flicks. The craze seems to have passed as far as I can tell anyway.