I need to read Butler and more Cherryh: I read Rimrunners ages ago, but other than that nothing except the Morgaine books (after you mentioned them here). Oh, and I guess a few stories here and there (e.g., in Heroes in Hell). Ditto for Duane, as I've only read her Star Trek books.

I've owned Ash for ages but haven't yet mustered the energy to read it. Real Soon Now.

I do not think I have read anything by the authors you haven't read except a short story or two by Gunn (I know I have read "Stable Strategies for Middle Management"). And maybe some stories by Abbey, but if so I can't recall them now - I never did read the Thieves' World books.