Listening to various German speakers I've noticed what I assume is a dialect difference in the pronunciation of 'ch'. German-speaking members of my family (some of whom learnt it at school and others who learnt it while living in Eastern Europe) pronounce it the way I always thought, as a /k/ or /x/. However a number of singers (including Nena) and a choir teacher at school, who has studied modern and literary German, pronounce it closer to a /ʃ/.
So is this just a difference between dialects or is it an issue of personal pronunciation? If you speak German, which pronunciation do you favour?