Let's see; X: the movie is a pile of unendurable filth that chops up and mangles the story and characterization so much that the movie will make your head explode. My head exploded and now look at me, I'm on this forum rambling on about anime. Just kidding, no head explosion here, though I'm made of some very tough stuff. I have been through the ultimate gate and survived.
Samurai Deeper Kyo, the reason; because it is such a generic samurai anime in existance. The story is redundant, the characters are so flat, stock, and uninteresting that the entire series turns out to be a big example in epic failure.