Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Ear Candy - Ear Candy is a sound level manager that nicely fades applications in and out based on their profile...
EarTrumpet - Volume Control for Windows
Audio Sliders - Volume Control replacement that is five times smaller than its Windows counterpart.
Volumouse - From authors website:
Sound Volume Hotkeys - This tool allows to control sound volume using system-wide hotkeys.