Best player for .avi and DVD's??

Hey guys...I was wondering which your favorite player is for viewing DVD's or any other video's? I am currently using the free version of Real Player on my XP OS. Windows Media Player 11 works well, too, but for some reason, the audio is always too low. There's Quicktime and some other ones. A friend of mine says he notices improvement in quality with Windows Media Player 11 over WMP 10. Is this for real? Do any of the players differ as far as video and/or audio quality?

So...which player do you guys like best and why? Take it easy everyone!

 

I like "The Core Media Player" Works well, and supports all my dual audio video files, ".ogg, .mkv, etc "

Check it out.
I also heard that there is an open source version of something like winamp that does DVDs to...I'll see if I can try to remember the name for it.

 

Free VLC, pay Jet Audio