General Alternatives:
* Last
* Ultimate
* Concluding
* Ending
* Closing
* Terminal
* Decisive
* Conclusive
* Definitive
Specific Alternatives:
* Ultimate (for something that is the best or most important)
* Culminating (for something that marks the end of a series of events)
* Concluding (for something that brings something to an end)
* Lasting (for something that will never end)
* Definitive (for something that is final and cannot be changed)
* Irrevocable (for something that cannot be reversed)
For Exams:
* Comprehensive
* Cumulative
* End-of-term
* End-of-year
For Decisions:
* Irreversible
* Unalterable
* Unchangeable
* Binding
For Events:
* Last
* Closing
* Farewell
It's important to consider the context of your writing when choosing a synonym for "final." The best word will be the one that most accurately conveys your intended meaning.