For best game, I'm wondering if Warhammer 2nd ed, with all of the backing of it's many supplements, might get an edge in.
For monster/adversary, I'm thinking, once again, about Warhammer for the Bestiary.
Best internal art I'd hate to see go to anyone outside of Dark Legacies as Adrian's art is top notch and anyone who hasn't seen it...
The catagraphy one was another twister. I'd say Dungeons of Doom, but City State of the Invincible Overlord is another good one.
Best Adventure probably be Slavelords or Trouble.