By now you've read our co-op review for Divinity: Original Sin... What?! You haven't?! Well, fine, then sit yourself down for the televisual feast that is our co-op video review!
If you don't have time for even video review, here's the quick and short of it: if you're a fan of RPGs, buy the game. It has a rich world to explore, has a good sense of humor, and a well executed combat system. Co-op is solid, but progress getting saved only to the host's game is disappointing.
The game is available via Steam and through Larian's website.