Though the horror genre has been enjoying something of a European renaissance over the last few years, the Japanese have always led the way as far as the most unsettling and disturbing movies go. From half-century-old classics that continue to endure to the latest button-pushing torture porn flicks and everything in-between, Japan are the masters of constantly erasing the line of decency and taste, establishing new standards of depravity and WTF-ness. These 20 movies represent the most screwed-up and terrifying that the Japanese horror genre has to offer, be they outrageously explicit films aimed to shock, or more psychological efforts that are no less penetrating. Whether good or bad, big-budget or shoestring, these are the films that won't leave your psyche for weeks after a viewing, and will surely have fans of the genre eager to see who can up the ante next. Here are the 20 most disturbing Japanese horror movies of all time...