As a matter of fact, the more plug-ins your install, the successful rate is actually not proportionally increasing. :^P
I suggest you follow these steps:
1) Uninstall all whatever plug-ins that you have installed so far.
2) Download GSpot, and use it to check out the actual codec that your AVI file was encoded with. (GSpot is a freeware, just search from Google.)
3) After you know the actual codec you need, go ahead and install it.
Some other suggestions:
Player: Media Player Classic is quite a good choice.
Codec:
For MPEG-4 video (including DivX3/4/5, Xvid), ffdshow filter is quite good.
For AC3 audio, AC3 filter is quite good. You might need AC3->AVI filter as well in some cases in order to correctly decode videos with AC3 audio.