Of the 'political compass'? Anarchist. Lower right is (supposedly, but doesn't seem to hold up when you look at the real thing) Libertarian.
Edited to add: But that's the thing actually! For example there are different forms of anarchism, ranging from 'no laws, no lords' to Syndicalism. Some want a form of capitalism, but without property rights, and some want communism, but without the Party.
And the same heterodoxy holds true for the all the other positions on the chart.
@irina @elduvelle
And don't get me started on political parties who are exactly the same in every dimension, except degree of racism or militarism.
On that chart the Radical/Conservative dimension should, at the very least, be broken into two dimensions for 'Socialist/Capitalist' and 'Nonconformist/Traditionalist'. The subsequent 3D context space would then allow us to separate political leanings this chart would converge.
That's my Battenberg Cake.