For real nice cinema sound I use a Soundblaster Live Player! 5.1 card by Creative. I use the driver that comes with the kernel:

Sound  --->
  <M> Sound card support
  <M>   Creative SBLive! (EMU10K1)
  [*]     Creative SBLive! MIDI

To setup everything install and run the alsa util config:

#> apt-get install alsa-utils
#> alsaconf

The Soundblaster Live is a 5.1 digital sound card. But for actually having a digital connection to my receiver I needed a fancy cable: The card does have a digital out port but it's a 1/8 minijack (basicly this is a mono walkman connector). Somehow I really had a cable with such a minijack on one side and a cinch coax plug at the other side laying around - don't ask me where that came from.

The next problem after connecting the sound card to your HiFi system is to enable the digital out. To do so run alsamixer and browse the mixer controls far to the right to a control labeled SB Live, hit the m key to unmute the control.

To be able to use the sound device as normal user you should set up some permissions and add the user to the audio group.

#> chown root:audio /dev/dsp
#> chown root:audio /dev/mixer
#> chmod 664 /dev/dsp
#> chmod 664 /dev/mixer