Dr Manhattan.
The only MMs who could possibly beat Dr Manhattan are MM with the power of the entire Beyonder race or Pre-retcon MM. But i wouldnt be mad at any takes that have Dr M beating those versions as well because MM was just all power and little awareness. Dr M has a level of omniscience and intimate understanding about the inner workings of the make up of time/space that i've never seen from MM or many other cosmics.