Illest rap concept album?

. . . well there's only like 3 that I know of anyways. Prince Paul's "A Prince Among Thieves" is some of the best MCing I've ever heard. The album fleshes out its story over the span of 35 tracks and boast a multitude of guest musicians (Kool Keith, Biz Markie, De La Soul, etc.) as well. I'm not gonna say much about it except that it one those albums that if you appreciate the hip-hop and rap community you owe it to yourself to check it out.

Prince Paul- A Prince Among Thieves (1999)