It's fun to argue about who is the best rapper in hip-hop history: Rakim? Ice Cube? The Notorious B.I.G.? Andre from Outkast? It's way less fun to argue about who is the greatest rapper in hip-hop history. As to that question, with its parameters expanded beyond matters of technical skill into overall body of work, cultural impact, stature and star power, it's becoming increasingly clear that there is only one answer and it is Jay-Z. He appeared on Saturday Night Live on Saturday (above if you have a life but not a DVR), performing a medley intended, surely, to whet the public appetite for the greatest hits album he's [...]