The two masters of their time. Contemporaries, rivals, Renaissance men.
It seems there is more historical significance attached to the works of Leonardo da Vinci, but was he the greater artist?
In my estimation: no. I believe the striking realism of Pieta contrasted with the imaginative splendor of The Creation Of Adam shows a more soulful, humanistic artistry than do the varied works of Leonardo da Vinci. I don’t think the sculptures of Michelangelo will ever be bested. The Pieta will stand until the end of the time as perfection chiseled of sweat and marble. It becomes a scene in your mind that you once witnessed and can only be fully remembered by gazing once again upon the stony embodiment. I believe it transcends all other artistic works.
That being said, sculpture may not be your thing and perhaps you consider the innovative, atmospheric style of Leonardo da Vinci more artistically affective. There is, of course, no right or wrong answer.