OMG... there's an ultraman movie... and boy is he fugly!
I mean, come on... simple is best yeah? Wat's with all those protrusions? Sigh.. another love of my life gone to dust.
There are other interesting Jap films. There's Casshern, which was pretty good. Gorgeous cg and a very layered, if a little TOO layered, story. Strong character development and action-packed.
Battle Royale, of course, is a landmark in story-telling. Violent, thought-provoking and ultimately great stuff.
And if it's possible, try to catch Zatoichi and Brother, both directed and acted by Takeshi Kitano. Good stuff... all of them.