Well this naturally depends on if you like whisky or not. But if you do and like blended whisky then the Blue Label is a great one, and best of all, it is available for self service in the bar area in the British Airways Galleries First Lounges at London Heathrow terminal 3 and terminal 5.
The Blue Label is the top brand of Johnnie Walker and definitely one of the best blended whiskies available. It is supposed to be made up of 16 different whiskies, making it a rather complex one with plenty of taste. Standard retail price is usually somewhere around 150 euro.