Batman/Grendel:Devil's Riddle by Matt Wagner
I wanted to read this book(s) since a long time ago.The plot is not very different from any typical superhero crossovers,but the narrative —both in story and art— is great,with lots of simmetry games showing how equal are both characters and how opposite are because of the same reasons.Most interesting point is the way both characters start clearly as a hero and a villain yet there's one point at which them both are anti-villains.