its hard to pick the greatest 'cause they all have their individual good points ;\ but overall tupac. everything about the man. He was way ahead of his time. He's like the John Lennon of Rap. heh. honestly though, smart dude.

biggie is amazing but his lyrical content gets a bit repetitive after a while ;[ although suicidal thoughts is my favourite song from him.

I rarely listen to pac anymore but my opinion hasn't changed =]