Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Sound Control - App-specific volume control
Audio Sliders - Volume Control replacement that is five times smaller than its Windows counterpart.
Power mixer - Power Mixer is a complete Windows volume control replacement.
Volumouse - From authors website:
Volume Scroll - Volume Scroll lets you control your main volume by hovering with your mouse cursor over the top...