Even thought Scott Snyder's writing on Batman has proven divisive, his run on the title has been consistently entertaining due to the excellent work of his collaborator Greg Capullo. (For the record, as I've said before: Snyder's scripts are ruthlessly competent if seriously misconceived, and the resulting stories are readable despite their general squalidity.) Capullo does great work, and what's more, he can actually produce a good looking comic book at a more-or-less monthly pace. The Nu52 Batman has been such a sales success that it's hard not to imagine that at least some of that success must come from the idea of a book with a stable and timely creative time, not simply a big-name writer working with a quick succession of hired guns brought in to satisfy an accelerated release schedule. If you bring in a different artist every other month, of course the result will be tonally flat, even if the books themselves end up looking pretty on an issue-by-issue basis. A writer producing scripts for multiple different artists at the same time will be unable to tailor his stories to the idiosyncrasies of his or her collaborators, and it's only once creators can take the measure of each others' idiosyncrasies that the truly exciting work of collaboration begins.
Anyway, one of the reasons why Capullo is such a good artist - and he is a very good artist, one of the best working for the mainstream right now - is that he is extremely adaptable. He brings the best out of his collaborators. He may have been completely wasted drawing Spawn for as long as he did, but he undoubtedly learned a lot from working for as exacting and eccentric a creator as Todd McFarlane. He learned how to draw like McFarlane and then learned how to draw McFarlane better than McFarlane himself could do. His work on X-Force with Fabian Nicieza was perhaps the Platonic ideal of what a post-Image X-book looked like, a little less flashy than the work that made it into Uncanny and the adjectiveless X-Men book during the same period, but also little more solid than the work that often showed up in the main titles.
But my favorite work of his, it should come as absolutely no surprise to anyone, remains his work on Mark Gruenwald's Quasar. Although he only drew the book for twenty issues, those twenty issues saw Capullo grow from a competent journeyman to someone who could take the reins for one of Marvel's highest-profile books before being poached by their fiercest competitor.
This is one of the most memorable scenes from his run on Quasar, and one of my favorite scenes from any run of any comic, ever. To give you a tiny bit of context: Quasar has just been completely blindsided and summarily defeated by Maelstrom. Maelstrom has taken Quasar's best friends as hostages, and in order to ensure their safety he has agreed to forfeit his all-powerful quantum bands. Malestrom takes the bands but - since they can only be separated from the wearer's body following his or her death - he also must take the wrists to which they are attached. He leaves Quasar hung up to die slowly by bleeding out, but not before being tortured by Maelstrom's minions. This scene has always stuck in my head because of the convincing manner that it signals a complete tonal shift. What had been a relatively bright and at times even light-hearted adventure book had taken a sharp turn into something far more dark and macabre.
It was a deliberate stylistic detour. By the time this scene arrived during the "Cosmos in Collision" storyline we knew that the book radically changed from its happy-go-lucky origins. Quasar had failed completely, manipulated by his supposed mentor, lied to since the very beginning of his super-hero career, and played for a patsy by an arch-villain he never even saw coming. Maelstrom attacked at his lowest moment, completely unexpectedly, and found Quasar easy prey. (In case you're wondering, yes, Quasar does die, but he gets better - returning from the dead is something Quasar does quite a bit, at least twice in his original run and a couple times since then as well.) In this scene he is at his lowest point, but somehow finds the strength to be a complete bad ass.
Quasar #22 (May 1991) by Mark Gruenwald, Greg Capullo, and Keith Williams.