I really like Spankmaster because of Yes Yes Y'all with Esham.
Although Keith has a great flow, and is obviously one of the more intelligent emcees out there - I really have to be in the mood for him, or else he can be off-putting. But I really like his voice, it's very unique, and Dr. Dooom rules!
Oh, and his verse on Esham's Tongues! Hell yeah Kool Keith.