A simple original question does not need us derailing the thread but OK
k-lite last I checked it was one of those really bloated packs and things do not seem to have changed:
http://www.free-codecs.com/download/K_Lite_Codec_Pack.htm
There is FFDshow and xvid and divx all in one. Likewise there are 5 main mpeg2 decoders (6 if you count the somewhat unstable part of ffdshow)
2 ac3/dts decoders/filters
and so on and so on
The "STANDARD" version is nominally better mind you by the looks of things.
VLC, MPC or GOM or even WMP
VLC, a fine player but not overly customisable.
MPC, pretty good but it is usually being used with FFDShow and co that makes it.
GOM, no comment as I have not played with it in several years.
WMP, urgh. Wait the bass audio filter is not that bad.
re: now new CCCP. As Mewgia points out it will work and you can do things by hand if it really becomes pressing (anyone on a vista machine should have enough to run nearly anything going).