Best software player CODEC?

[Fluffbutt]

I'd like to find out what's the best software dvd player codec (they all install their own codec, and most can be used without the main application).

For eg. I've found that Ulead player's codec is louder that DvdX player's, and the bog standard freebie dvd codec is very quiet, and a little 'frame - slippy' on the video.

I use Media Player Classic, and just use regsvr32 to register or unregister the various codec (of which I'm collecting a few!).

Anyone have any thoughts about the best codecs? (Note, NOT the best actual software players!!)

[Fluffbutt]

Additional:

Cineplayer video codec is very clear and sharp, but the audio codec won't work on its own.

Intervideo Video codec is EXCELLENT, it is really sharp (but not over sharp) and clear.

Audio codec is funny, on my SB Live 5.1 but NOT using the s/pdif output, I HAD to enable s/pdif in the codec or there was no sound.
This codec is absolutely fantastic!!, and it works perfectlt outside of any Intervideo product.
<quick update - on dvd's the video codec is a tiny bit darker (contrastier (is that a real word??)) that the other codecs. I still love this one tho!>

[Fluffbutt]

And the cyberlink codecs are as good as the Intervideo ones.
It allows sound output on channels other than s/pdif (great), and has stereo expanding and such like built into the codec.

Hard to choose between this and Intervideo codec.