*Darkest* triphop albums

I need some new music in my collection and I just wanted to see what people might suggest. In your opinion, what are the best, darkest triphop albums out there? Probably a little vague of a question, but I'd like to hear what you think all the same. The more I listen to various triphop artists, the more I like the darker stuff, and the darker the mood the better. Thanks in advance.