Of all the mediums that influence language, I think film is the one that has the most effect. Not so much from the point of view of pronunciation and grammar. I don't think we pick up very many sounds and grammatical [bad word] from the films we see – but the catchphrases. Right from the earliest days of film, catchphrases have been extracted from the film medium and "make my day" I think is one of the most famous. 

Well, you may remember it, it's Clint Eastwood, isn't it, playing Dirty Harry in the film Sudden Impact. He invites an armed thug to take him on and Clint Eastwood is holding a very big gun – so he's just waiting for the thug to do something horrible, and he says "go ahead, make my day!". 

Well it just caught on, it spread in meaning – people started using it, of course not with guns in their hands, they started using it within a sort of ironic circumstance. To say "make my day" means "do something that'll really please me". It implies a really big deal or something like that. In fact Clint Eastwood himself, when he was being elected mayor of Carmel, went round the whole of his little town, his little city, with a T-shirt on - "elect me mayor – make my day!" 

 [bad word] /www.bbc.co.uk/worldservice/learningenglish/radio/specials/1728_uptodate/page2.shtml