It's impossible to argue with "favourite" when it comes to selections of this kind (although one can always opt for snobbery at the tastes of others, something I am disinclined towards, except in extreme cases where I can no longer keep my mouth shut). "Greatest" on the other hand, that's a different matter. Still subjective, but much easier to make a case. Raiders of the Lost Ark would have been my 1981 choice too, but... Well, the reasons are in my article.