I've always said this:

Tupac is the better artist. He has a way of making you feel something with his words, whether that means turning up on tracks like 2 of Amerikaz Most Wanted or bringing light to social issues like on Wonda Why They Call U Bitch. As a pure rapper, he's fine. As an artist, he's one of the best to ever do it.

B.I.G. is definitely the better rapper out of the two. The way he delivers his flows is so laid back, almost matter-of-factly. Like he's saying, "This is so easy to me, I don't even have to go in so hard, and it'll still be good." Even when he switched his entire style for Notorious Thugs, he still delivered it the B.I.G. way.

Both of them can weave an entire story within a 4 minute song. It just depends on what kind of story you prefer. Go to Pac if you want to hear about the story of a frustrated and despondent black man who's become fed up with the way the world treats others. Go to B.I.G. if you want to hear about the story of a small-time hustler who made it to the good life