Today there are many MP3 players like Windows Media Player, Winamp 3, Music Media Juekbox, Sonique etc.But the in all of these the best I think is Winamp 2x series.
The best part of it is that it does not take much of the PCs resources.If you try to start it even on a 100 Mhz PC it will start(I have my PC speed of 500 Mhz).Whereas if you try to load Windows Media Player, Winamp 3 etc. they are high on resources. If you have a PIV machine then theres no problem but it takes a hell lot of time on low-end PCs.
If you get bored looking at the same skin you can download it from the net or from the cd. Most of the magazine which give free cds always include Winamp 2x series skins coz it does not take so much space on the cd or time to download.Where as if you download skins of Windows Media Player, Winamp 3 its skin download size goes almost above more than a MB.
You may think that Winamp 2x is low in output as it does not give expected quality of sound you would expect in Windows Media Player and Winamp 3, theres also an option to have DSP effects.One of the popular DSP effects is DFX which you can download from https://fxsound.com. DFX also includes for Windows Media Player and Winamp 3 etc. But you dont need for them as they have additional features.
No Doubt it lacks features of WMP 9 like Crossfading but I think its still the best.