Spooky:
Best quality playfields/clearcoat
Best factory audio/speaker systems
Real backglasses in all game models
Best standard powdercoating
Stern:
Best flippers
Best themes
Best rulesets
Best layouts
Games play great out of the box
Generally the most fun to play
JJP:
Best attention to detail
Fit and finish
Best LCD graphics
Best lighting
Premium feel
Unique mechs and toys vs. Reusing ideas.