Of late, one headphone that reviewers seem to be comparing to Stax 009 is the Abyss AB-1266. It seems to have the best of HD800 (imaging) and the LCD-3 (Bass and easy to listen). It's of course $5495 and seems to need an Amp as powerful as the Taurus Mk2. I plan to borrow it for a while to see what all the fuss is about.
Personally, I have the HD800 and the LCD-3, which complement each other very well. HD800 for Orchestral and Big Band music and LCD-3 for all my other genres.