Here are some I'd like to see:
Alakol, Salatu, Rasana Style
Ancestral Lands style
Cave style (I was thinking of a pitch-back style, since the one we have already has light patches)
Ilmenskie Caverns Style
Both Ix styles
Underground (Switchback, Blue Mountain Bore,) style
House styles:
Mansion style
Uncle Friendly's Emporium
Bureaucratic Hall
Post yours here!