By never written Thor I'm mean never written on the main Thor comic. Minis don't count so if you're a Rodi or Busiek fan, they're fair game. Personally I would love to see Grant Morrison take a turn at Thor.
A few Names
their work on Star Wars over at Dark Horse is amazing. "Their" character of Quinlan Vos was so popular that even George himself was impressed by the success the character had (especially since Vos was never in a film).