What (or who) is your favorite VR Theory / Text / Designer?

What (or who) is your favorite VR Theory / Text / Designer? What really helps you design (frames your approach - defines the problems you want to solve) ... personal takes here are fine - BUT, I'm compiling a list of (published/peer-reviewed) stuff at isovista.org (database > theory page)

Some broad ideas come from Game Design (Narrative & Interaction) - Literary Theory (flickering signifiers / hyperreality) - Engineering (usability) - Architecture (transArchitecture, isovists) - and more.

3D Data Viz theories in particular would be great.
If you have no favorites... (do you feel that's a problem?)