I use Windows Media Player 11 for most of media files the ones it can handle like .mp3, .midi, .avi, .asf, .wma, .wmv, .mpeg, .mka, .mkv. .ogg, .ogm, etc. I use the latest RealPlayer for realplayer files. I use the latest Quicktime for quicktime files. I use the latest Winamp for .nsa, .nsv files. My recommended codec pack is the latest version of Matroska Pack and Ogg Direct Show Filters 0.9.9.6. For DVD playing I now use Cyberlink
PowerDVD 6. I use this because it came with my DVD player. I always recommend using the one that came with your computer or with your DVD player.