I voted Wheel of Time, partly because it's the only setting I own of those mentioned, and of course because I think it's a great piece of work. Reviewing the list I find that Black Company would probably be my second choice since it's the one I'm most likely to buy.
And leaving all that D&D-based crap behind ( ) I'd like to give an honorable mention to Sidewinder: Recoiled which is the setting I've read the most lately.