And also elements such as lyrics, flow, creativity, substance, delivery, everything that makes up an artist. Limitless aspects though. Pac is my GOAT because he had the diversity within his music, has so many classic songs, KRS-One up there because of the incredible content and music he's done, the unique way he would tackle topics, styles, so much, and K-Rino up there for incredible lyrical ability, amazing diverse body of work, that emotionally touches you and verbally impresses, and Nas for aspects amoung many great albums and classic songs, and certainly creativity, he has a lot of concept/creative songs which I really respect.