No Hicks? 
I would have assumed an Atlas poster might have included Coase or Arrow or someone but you've clearly taken a classic internet libertarian route in making this list.
Yeah, Hayek was not an actual economist. Political theorist/philosopher is a more accurate description.
Pretty sure Ricardo deserves a spot in the top 10.
Hayek is a respected figure in the economics profession. Von Mises, of those on this list, would be more of a problem. Along with Marx, he shares the dubious distinction of starting a religious cult. But, at least, Marxism has been influential.
Hayek was absolutely an "actual" economist. It's not (entirely!) his fault he's been attached to a bizarre ideological movement based around some of his more archaic ideas.
Nobody forced him to write
The Road to Serfdom, as far as I know.
