Actually i thought the ring was better than ringu
probably because i watched it first, the stories werent all that different but he cinematography in the us version was better
for the fear factor it was a pretty dull movie from either side of the ocean and it is far from my favorite movie from any country
its too difficult to choose a favorite movie but of course i like kitanos work although i find his newer stuff boring, that said zatoichi was 10 times better than dolls
i really like one movie called laundry (ﾆ停?ｰﾆ停?愴檀ﾆ椎?ﾂーﾂ） starring koyuki and kubozuka yousuke
All About Lily Chou-Chou is a stunning movie by Shunji Iwai - some may find it a little over-long (i think its just under 3hrs) but its a great film.
It's a study into the life of a teenager whose life (along with numerous classmates) is turned upside down as a result of bullying. Far from a preachy film it explores the cause and effects of bullying which in some scenes is emotionally devastating. A hard film to watch (hardly a friday night with a few beers film) its hugely recommended so long as you have the patience to give it a try.
For an introduction to his work that is a lot lot more accessible - you could try his other films such as APRIL STORY, or LOVE LETTER.
Iwai also made "SWALLOWTAIL BUTTERFLY" which was acclaimed by critics and fans but left me cold (im still yet to have finished it).