Basic -

AC3 Filter 70b -
DivX 5.05 Pro -----> Change it to any version you like
XviD-1.0-Beta2- 05 12 2003 --------> Same
AAC - Setup ACC -----> Download at KAA Site
ffdshow - 2004 05 08.---> Turn on the Xvid Codec part.

MKV/ OGM-

OggDS0995
Matroska_Pack_MPEG4_v1.0.2 or Matroska_Pack_Full_v1.0.2

Players -

The Core Media Player - 4.01 - PLays OGMs and you can pick the font.
VLC ---> I hate this one...but its always good to have.

Other
G spot

Thats my setup, but i have almost every build of alot of them, so i can change at any time. Anyways, this setup hasnt ever failed. AVI, MKV or OGM are no problems for it. But to each his or her own, ya sorta gotta pick whats best for you. I hate packs, cuz they use to crash my stuff.

Well thats all i got to say...