I think this is less political and more philosophical. However, the answer has profound political implications I think.
Now there are obvious extremes that everyone would agree with. There are some very obvious forms of slavery, such as forced labor or sex. Also, there are obvious examples of the free man, such as the 1800s frontier farmer who is beholden to no-one.
What I am more curious about is people's thoughts about the more borderline cases. Examples could possibly include taxation for things a person does not like, oppressive social expectations (a woman belongs in the home!), forced life choices due to constraints, etc. Are these things an example of a type slavery or not? Why?