The popular open source multi-platform media player VLC will let you increase volume up to 200%, if you are using the volume slider. This applies even if you are increasing the volume by placing the cursor above the volume bar and using a scroll wheel or a touch pad to control volume output.

If you scroll the wheel or touch pad outside the volume bar while the VLC window is active, it will allow you to increase the volume till 400%, double the limit of the volume bar. So if you are a music freak and like it loud, you know what to do.