This is the worst match-up of all-time.
What are you trying to accomplish here?
It's gotta be DC for me. I love Spawn (not much of an independent-of-Big-2 fan), and I love a lot of Marvel crossovers and teams/team-ups, but Superman, Batman, and the Justice League are just my jam.
I would say that it seems like DC has more 'original' characters (i.e. Darkseid preceding Thanos). This might be a more interesting poll than versus TBH. It's probably been polled at least a dozen times, though.
Edit: Nebula vs Gamora