Tip 1:
For watching DVDs (.VOB files), I use Cyberlink PowerDVD.
Tip 2:
For all other video files I use GOM player because it has every function you will need while watching movie file of any type.
Tip 3:
I have kept VLC player only as a reserve in my PC... believe me, I use it hardly ever.
Tip 4:
You have to install K-Lite Mega Codec Pack for GOM player but not necessarily for VLC player (it can play any video). Anyway, you will need a codec pack for video editing tools.
Tip 5:
For all music files, I use Winamp because I like its colourful skins (hide the video window).
