Watching Hong Kong films and dramas is how I maintain any semblance of my bilingualism (bilinguality?) I regress fairly quickly though. I also get peeved when whatever I'm watching turns out to be dubbed over in Mandarin rather than being in the original Cantonese. Mandarin may as well be a whole other language to me.

As an aside, Sleeping Dogs really got me back into swearing in my native tongue.