Battle Royale uncut
The Returner
Versus
Kung-fu Hustle
Sukeban Deka 1
Shaolin Soccer
Vampire Effect
Ong-bak
Iron Monkey
My Vampire Effect film goes by the title Twins Effect. A fairly fun film. Much better than its crap sequel which has nothing plotwise share with the original, simply the twin actresses.
Returner always seems to get a bad reputation for being all flash with no substance. I say "meh" to those complainers. The film is an awful lot of fun & that's just fine by me!
I've been a fan of Versus for a long while now. Did you get the original version or version 1.5? I've thus far only seen the original version. Does your DVD release of the film have the bonus material / footage? Don't allow that stuff to go unwatched! I dare say that some of that material is as entertaining as the film itself! I wouldn't be nearly as much of a Tak Sakaguchi fan had it not been for seeing him candidly.
Did you check out Azumi based on the idea of following Ryuhei Kitamura? Ryuhei is great, but I have yet to see any of his films that I have taken to as strongly as Versus. (probably about 5 all together)
If you wish to follow Tak & have a very lenient sense of humor, I urge you to check out Battlefield Baseball & Snot Rocket. Both are goofy but quite fun.
Sukeban Boy - Have you also seen Noboru's Machine Girl? It's absolutely worth your time. Following those two you will need to see Meatball Machine (from director of Battlefield Baseball & Snot Rocket), it very much keeps in the theme of Human/Technology. ..Following that there are of course the classic Tetsuo movies. A tad on the artsy side, but worth the watch.
I haven't seen Tokyo Gore Police yet (despite it resting right beside me on my shelf), but it seems to also share many of the same themes.
The other films that I singled out were simply for the sake of offering a thumbs up for good film /fun, anyways ;P