If you have a reasonably effective international court that monitors human rights violations in a number of countries, then the number and severity of judgments of this court can be used to measure respect for human rights in those countries and compare levels of respect.
The ECHR was set up in Strasbourg by the Council of Europe in 1959 to deal with violations of the 1950 European Convention on Human Rights in the 47 member European states that are members of the Council (not to be confused with the European Union). It’s probably the most effective human rights court in the world today – which doesn’t mean that all its judgments are respected. Citizens in all member states have more or less equal access to the ECHR and the court applies the human rights convention equally to all member states. So this should give a useful and internationally comparable measurement of respect for human rights, at least for this subset of 47 countries.
It’s clear from the map below which countries most commonly fall foul of the ECHR:
(source, where you can find an interactive version)
In 2011, the European Court of Human Rights found 159 violations against Turkey, 121 against Russia and 105 against Ukraine. Of 1157 judgements pronounced in 2011, the human rights violations most frequently found by the court were in the length of proceedings (341), the right to liberty and security (241) and the right to a fair trial (211).
One can expect more judgments against more populous countries, of course, but there’s no clear link between population size and number of judgments, which confirms the intuition that some European countries are more free than others.
More posts in this series are here.
Update: a more complete database is here.

(The second link under the map “where you can find an interactive version” is not working.)
Finding Ireland, Norway and Ukraine on the same score — 100% — suggests it is not the most useful of measures.
Click on “source”. Norway is strange indeed. Finland is a lighter shade as I see it.
Yes Finland is a different colour/shade. But it is not one of the three (of seven in total) with 100% “scores” that I named.