Artist who is a rapper? It would have to be Kanye West. In just looking at rappers, I would say Eminem. I distinguish between music genre creators and artists, I feel like the label artist should be applied to people with broader output than just a music genre. Kanye directs, produces, raps, designs, etc, and has just such a revolutionary "artist" attitude. You may call him an egotistical maniac, but he plans to make emotional music, does, and has been hugely successful. He plans to have designs in high fashion, and has already entered the designing game. He says he is this generation's Shakespeare, now you might say that's arrogant, but I'm looking at it as a goal he has set for himself, and is passionate about accomplishing whether or not people agree with him.