Goblet: SK, Ghoul & Diabo or Micheal
Strife: Santa, Warlock lil nick & Diabo or DD
Rock: micheal Diabo or DD
Victor: Druide, Vlad, Dusa & for the rest, what you use more often
I don't think heroes have specific best Artifacts, but this is my general trend:
Victors: I consider this my overall favorite default crest. Unless I need a specific hero to crit for maximum damage, I put the hero here.
Lightning Rock: I only use this on heroes I want to stack dodge/sprint on.
Blitz: PD or Minotaur
Axe: This is only when I need to maximize damage, such as Arch Demon, or Mino Bomb.
Eye: I keep Ghoulem in here full time, for no real apparent reason.
Goblet: I use Goblet for primary tank heroes.