If "obliged" means "feeling grateful":
* Ungrateful
* Unthankful
* Indebted
If "obliged" means "forced to do something":
* Free
* Unconstrained
* Voluntary
* Unbound
If "obliged" means "to be indebted to someone":
* Independent
* Self-sufficient
* Unencumbered
It's important to consider the specific context of the word "obliged" to choose the most appropriate antonym.