It all depends on the listeners taste really...
You will normally have several presets for music, speech, sport, cinema etc. I'm assuming that the tv displays several slide bars? If so, as a general rule decent sound quality is achieved by setting them like a smiley face. (ie: if there are 5 slidebars then the left one will be +50, the next one 0, the next one -50, the next one 0 and the one on the right +50) Then tweak slightly to suit your own personal taste.
I normally put a music channel on and try to get the best sound possible from that.
Andy
June 2011