I'll just comment based on the designs I like best, not necessarily the most original or most diverse.
Bob Loveless: IMO a true design genius, perfect designs no frills simply beautiful
Jens Anso: many clever designs, very original and recognizable; one of the simplest of his designs (the sheepfoot necker) is IMHO one of the best necker designs ever.
Tom Mayo: the TNT sets the standard for apparently simple, perfectly useable yet beautiful and ergonomic custom framelock. Great variety too, in both size and shape.