General:
* Finished
* Depleted
* Exhausted
* Consumed
* Spent
* Empty
* Gone
* Vanished
* Disappeared
Informal:
* Out
* Used up
* No more
* Done
* Kaput
More specific:
* Extinct (if referring to a species)
* Destroyed (if referring to something that was damaged)
* Lost (if referring to something that is missing)
The best word to use will depend on the specific situation. For example, if you're talking about food, "finished" or "consumed" might be appropriate. If you're talking about a resource, "depleted" or "exhausted" might be better.