If you are using Mac OSX & like using QuickTime player, check this list also
.avi ~ sound but no video in Quicktime (Click on blue link). I
highly recommend Perian plug-in codec, and also VLC & MPlayers just in case. MPlayer I'd recommend the OSX beta version. Depending on the file, some I set to open with VLC, some with MPlayer, some with QuickTime Player.