if youve got a decent stereo as it is then you probably only need to buy a modern amp with all the right connections for it.
most new tvs will have either a phono or optical outlet for sound, you can connect your tv to the stereo with an optical cable for best quality, might need to fuck around with the sound settings on your tv though?
i prefer the sound from all of my gadgets to feed straight into the amp, i just use the remote to pick whichever i need at the time, i dont trust the sound processes in my tv at all (given that the xbox, cd deck etc will all have their own sound processors fucking around with the sound output, as will the amp, cuts out the middle man in my head)
the only one that uses the optical cable from the tv is my virgin media box, which is normally only used for watching sky sports or shitey tv programs, i dont care if the sound is any good. everything else feeds directly into the amp and so far nothing hasnt worked in terms of sounding surroundy or good
