I would be curious about your favorite coop games. I often find them a big lacking, often being a bit unbalanced. An example is Battle for Hogwarts, where one game can be a walk in the park and another absolutely impossible and rarely is there a balanced match.
Terraforming Mars isn’t strictly coop but it sort of has a coop aspect to it. You could play it as a coop if you wanted to (try to terraform mars before X number of generations).
Edit: turns out someone has actually written up a pretty comprehensive set of new rules/instructions for a coop variant on BGG https://boardgamegeek.com/thread/2009605/man-against-nature-cooperative-variant