This is quite the controversial topic... Anyways. Is this the non-canon variation or the canon variation ? Depending on, it is either one sides victory or the others.
I'm assumign the Tier 0's are out because of obvious reasons. I'm going to split this up into two sections : Non-Canon and Canon variations. Because i am going over everything currently... As you are talking about DC and Marvel as a whole
Comic Canon Analysis : DC has more tier 1-A's and one High 1-A . Marvel's are baseline. They oneshot for the entire group. Some of DC can beat Marvel, and some of Marvel can beat DC. However, to figure out who beats who ,
Comic Non-Canon Analysis:
The opposite is true. Marvel beats DC becuase of how ridiculously powerful their non-canonical versions are, to the point i am very happy that they decided to be much different than they were before . Wizard Merlyn non-canonically scales to 1-A's [ They strictly performed a "Beyond the Concepts of Time and Space" feat, to the point it's not even up to interpretation of feats ] , and Otherworld Merlyn views said 1-A's in their totality as nothing but a chess-board game and fiction , and yet an aspect of the Phoenix Force easily oneshots him . True Phoenix is considered much weaker than the Cosmic Abstracts back then. I'm not going over everything [ Including the old definition of Omniverse, which is canon to the non-canon at the time , which only the God Tiers and a particular Mutant scales to, which would make them stomp here ] , but before they were consistently put at High 1-B , the Abstracts were that strong, to a non-sensical level . I would review DC's non-canon, but that is far too much to go over, but most of them have lower showings than they did before, in acception to the Old Gods, who back then were High 1-B as opposed to 2-A .
I'll go over the Cinematic and Animated variations momentarily.