Zoom Player Professional is really the only acceptable option. It's as "light" as media player classic, vlc, etc. but far more flexible.
"Zoom Player was designed from the ground up to load quick, take as little system resources as possible, provide user feedback/direction as appropriate and maintain as much isolation from other applications and system components as not to undermine overall stability.
Zoom Player is fully scalable, supporting all the latest media formats and interfaces. New features are incorporated on an ongoing basis with release schedules and feature integration clearly announced on our support forums.
Zoom Player is capable of playing all common media formats and quite a few of the not so common, including:
AVI, Matroska (MKV), QuickTime (MOV), Cellphone 3GPP (3GP), Flash (SWF), RealMedia (RA/RM/RMVB/RAM), Windows Media Format (ASF/WMV/WMA including DRM with WMV Professional version), OGG Movie (OGM), MPEG1 (MPG/VCD), MPEG2 (MPG/SVCD/VOB), MPEG4 (DIVX/XVID/ISO), VP3-VP6, MPEG Layer 3 (MP3), Vorbis Audio (OGG), Dolby Digital (AC3), Advanced Audio Coding (AAC), MusePack Audio (MPC), FLAC Audio (FLAC), OptimFROG Audio, Monkey Audio (APE), Wave Audio (WAV), CD-Audio.
Zoom Player comes in multiple flavors:
Zoom Player Standard, a flexible feature rich Media Player that for all its features and goodness remains bloat-free, Zoom Player Professional, which on top of being a great Media Player, incorporates the most powerful DVD Front-End you could imagine (and even a few features you didn't think of imagining) and Zoom Player WMV Professional, adding Windows Media DRM playback support.""