http://i100.photobucket.com/albums/m35/fla_vistadude/ms_vista_sound.jpgXP Codec Pack is one of the most complete codec pack which helps you to play all major audio and video formats. And… to complete your multimedia experience, instead of 3 or 4 different players you get one, simple integrated player that plays almost all audio and video files: Media Player Classic.
Download: XP Codec Pack 2.0.7.1
Source: XP Codec Pack
**Ace Mega Codec Pack **
It does look like there are difference’s but you will have to caompare both packs and see. I also found another pack that is huge. It is called ACE Mega CodecS Pack 6.03 - Professional Edition.
Download: Ace Mega Codec Pack