As a rapper, maybe. He was VERY popular, but amongst hip hop heads, he was never really considered one of the "best" MCs.
That's it really. He sold records but never got much attention from the scene. It would have been a risky choice for me to drop a 'Pac song at a gig back in the day. Biggie had far more cred.
tupac had so much emotion in his songs, so much soul. you could really feel the honesty in what he said, even if it was sometimes hypocritical
The problem with the hypocricy was it made the emotion hard to take at face value.
The fact that he became famous when he's dead and he lead a film worthy life, don't make him a great MC. I wouldn't rate him in my top 50, I don't think. Hell, Shock G was better than him any day.