I used WMP, RealPlayer, MPC, iTunes, WinAMP ( not the latest versions ) and some other stuff
I would say that I never found an all-in-one player like JetAudio !!
JetAudio has two versions, Basic and Pro, the Basic is absolutly free, while the pro adds some more functionality like Video covnertor and Advanced Audio convertor too...
The player can be minimized to system tray and you can completly control it throught normal media keys in your keyboard ( Play, Stop, Next, etc.. ) or you can set up a shortcut keys of some key combination as you wish for most features...
the latest version 7.x comes with an improved and redesigned Media Library, wich is far far advanced than older version, now the player is absolutly the best...
you may play almost any type of audio & video and use some advanced effects too...
the player also support skins, so you have some wide range of skins even if I personally likes the basic one that comes with the program
maybe there's one draw back wich is memory usage wich in most cases be around 15 to 20MB, but some times go over 20 but less than 30MB, but all this depend on how long you use your computer without restart as I keeps my PC always on, and also 20MB is nothing if you have good amount of RAM ( I have 2GB's )
the only thing I miss in JetAudio ( and all other players except WMP ) is the toolbar mode that some how becomes a part of your startmenu bar, I found this first on WMP, but I don't see it in any other player...
but as JetAudio supports keyboard shortcut, you may not even need to waste some space in your startmenu bar too !!