It is always essential to have a right media player to play the files that are available.As the number of file extensions increases the need for the right player too increases.It is always hard to find the best ones as there are a lot of players available outside.According to my experience the ones i was interested in are the following
1.VLC Player
VLC player plays almost every file format.It is much more advanced than other players and comes under a GNU license.Everyone can easily get the source code and if needed they can modify it for their own needs.This is available for both Linux and Windows os.It is absolutely free.

2.Winamp
Player from nullsoft which is a well known player since 1997.It is a very good player for playing audio files but not much better in case of video files.It has a modern interface and offers easier use.It has a lot of skins available over the internet and a lot of sound enhancement options too.But Winamp pro comes with a price tag of $19.95.

3.Windows Media Player
This is an inbuilt player in the windows os .A large amount of people have been using this for years.It is stylish in appearance and has a good amount of codecs too and is available for download as a kit.It has sound enhancement options like DFX.Micorsoft has been constantly updating this player to better standards.

4.KMPlayer
I came across it only a few months ago.But it has a lot of good options which makes it an excellent player.It has a large range of known file formats bundled to the installation file.It has the advantage of playing all the files in a folder with selection of only one file thus avoids the pain of making a playlist.

5.Real Player
A nice player with advanced video streaming features and specific movie formats .It is being used by a lot of people and has a pleasant appearance.It is also available with more advanced features that comes with a price tag.