Dahlia by X-Japan is easily my favorite album of all time.
It's 'lost' because they are a Japanese Band and really no one listens to Japanese music. Most people are turned off by the fact that most of their lyrics aren't in English. I always tell people that the singing, even if it is in another language, is simply part of the total music experience. This album is really unlike anything I've ever heard before. With a good mix of post-modern rock and traditional ballads, it really has everything I love in music. Here are a couple of Youtube videos of songs off of the album:
Kurenai
Tears