As long as it tastes like tarmac and molasses, doesn't burn the mouth at full cask strength, and has a licorice finish I'm not picky. Ok, so that narrows it down to like two Islay spirits at +$100/fifth that have rested in a charred xeres cask for at least 14 years, but a bottle lasts me a very, very long time.
Now a level five Soduku puzzle, that might take me more than 3-5 years to get right!