These tips will make your Winamp play music louder and with higher fidelity without buying a new sound card, like Creative SoundBlaster.
Install MAD MP3 decoder. MAD represents the decoded audio signal with high precision. It supports MPEG-1 and the MPEG-2 extension to lower sampling frequencies.
Enhancer 017 is the best DSP plug-in for Winamp and it's free. Try "General improvements" preset. Other great presets: "Treble boost", "Party with ambience", "Inside the music".
Although it's outdated, some hardware work better with waveOut output. Go to Options / Preferences / Plug-ins / Output and select waveOut. You can read more about DirectSound vs waveOut.
Listen to Pandora in Winamp
If Google made a media player