Firstly if you're looking for high brow, intelligent humour to watch with your Grandma then this probably isn't the film for you.
However if you want to escape all that's going on in the world for a couple of hours, listen to some amazing music and laugh to childish, un-PC humour then this may be for you.
I have watched this film countless times - more than any other - and it still makes me laugh and the music helps to put you in a good mood.
As I say a marmite of a film but give it a try if like things like the Inbetweeners films etc .