Best Free Media Players

Best Media Players
Here is a list of best media players for Windows.

VLC Media Player
The most feature rich and stable media player. It's free and open source, maintained by a group of volunteers. It supports a large number of codecs. Updates are realeased regularly. Aprt from video it can play audio files too.
VLC can be used as a streaming media player.

K-Lite Codec Pack
Another great media player with support for all major codecs. The interface still resembles the old Media Player but comes with support for a large number of codecs.

GOM Player
GOM player can play all major formats including formats popular on mobiles like 3GP. GOM Player has a modern interface.

KM Player
KM Player is from Korean software company. KM Player supports all major formats,

PotPlayer
PotPlayer is new in comparison to other players but it is fast and lightweight. It uses techniques like CUDA and DXVA to deliver maximum performance in available resources. PotPlayer supports a large number of file formats, perhaps even more than VLC Media Player. PotPlayer is currently available for Windows only.

Conclusion: All media players listed above are stable and can play all mainstream formats. Final choice of a media player may depend on user's preference of interface or requirement to play a rare format.
These media players can be used interchangeably. Personally, I have all of them installed on my PC.