Hmmmm...hard one. I prefer EL-P as both a writer and producer in general, but to suggest Kanye hasnt produced some amazing albums is idiocy.
Kanye as a whole probably has a stronger catalog with its depth, however EL-P created a new sound and between Cold Vein, Fun Crusher Plus, RTJ, and his solo projects I prefer him.
I think Kanye is obnoxious, but they both put in work.