you should all check out the Beef series on dvd if you haven't already, has some amazing stories and background lyrically and physically between some of the greatest, kool moe dee vs busy bee, krs one vs mc shan, nas vs jay-z, the internal battles of nwa, epmd and all that
here's a teaser of the krs and shan one
http://www.youtube.com/watch?v=mDZoFnfyquE&feature=user