Official is a word which me and my friends have used for many years, we use in the context of which proucts or person etc is supperior and therefore the best. As a rule the first of a particular product is automatically official, however a product can overtake another with superior price or quality.
If the person for example is annoying and you dislike him you may then to decide to use the term unofficial which is basically everything which is not official.
Finally the last context is an act done by someone, which is pulled of perfectly and is generally good all round. If however they bail that is unofficial.
There are other contexts obviously but far to many yo put here (e.g. place, name, colour etc) so use in whatever context you like, but make sure its an official context.
Product: "heinz ketchup is official!", "this own brand ketchup is so unofficial".
: "saterlite tv is official", "cable is unofficial"
Person: "God dam, that lad is official", "Dean Whitehead is so good at football he is official".
:"Alan Shearer is whack he is the most unofficial person i have ever set eyes on!"
Act: "woah downed a pint in 5 seconds thats official"
: "he tried to claim shotgun after i called it, thats unofficial!"
Place: "Newcastle is official, Newcastle United are the most unofficial football team in the world!"
: "Shefield is a shit hole its sooo unofficial."
: "Sunderland AFC are the best team in the world they are official!"