Georgia was one until two weeks ago, at least
de facto. The language wasn't quite as clear as California's, but it was essentially impossible to enforce non-competes. A bunch of big companies managed to get an initiative on the Nov. 3 ballot to overturn that, though, and it passed, partly due to misleading language that's currently being litigated. The ballot question read,
Shall the Constitution of Georgia be amended so as to make Georgia more economically competitive by authorizing legislation to uphold reasonable competitive agreements?, which is a bit, uh, indirect about the fact that its main impact will be to legalize noncompetes in GA.
It caused a bit of ruckus within libertarian-leaning circles in Georgia, with some people lining up on the pro side, arguing freedom of contract, and other people lining up on the anti side, arguing right-to-work. It was probably the only major issue where progressive groups and tea-party groups actually had the same position (against), but they were both greatly outspent by the Georgia Chamber of Commerce and business-Republican groups.