Scotch Whisky lasts for decades in the bottle.
It is not true that whisky will get bad or loose taste within 10-20 years as told by the above poster. Whisky will remain unchanged in the bottle for decades - some prewar whiskeys are still drinkable and are not changed in taste. It all depends on the sealing of the bottle. If the bottle is well sealed and stored in more or less stable climate whisky will be perfect. Whisky is high alcohol content and is stored in glass is basically inert and keeps well a long long time.