I propose a new category: Best Use of Teamwork.
These will be the best scenes involving the use of all or many characters, complementing each other's abilities/powers/skills without grandstanding the poster's own character or making that character look better than the others.
Teamwork is something I'd really love all of us as writers to focus on from now on, personally. We give a lot of lipservice to it, but it tends to get lost in the shuffle while we're actually writing the stories.