I've seen
Ringu, Ringu 2, Ringu 0: Basudei, and
The Ring. I thought
Ringu was the scariest of them.
Ringu 2 didn't make much sense and sort of did its own thang, and
Basudei...well, I loved it because Ban Daisuke* was in it (he was Sadako's dad, Professor Ikuma) and he finally got to do more than just rush at the camera with a machete or whatever it was he had in his hands to do in Sadako.
But, I have to admit, when I was watching
Ringu the first time, our own phone rang during the movie and my husband and I both screamed like little girls. Ugh.
I never saw the original
Ju-On, but I did see
The Grudge and it scared the heck outta me. But it takes a lot to beat Sadako crawling out of the TV set in
Ringu!
* Tokusatsu and sentai fans should recognize him as Jiro from
Jinzo Ningen Kikaida, Goro from
Inazuman, Makoto/Battle Cossack II from
Battle Fever J, and Izumo from
Ninja Captor, among others...