For an incredible music experience: Open Windows Media Player: - Click View - Click Visualizations - Click Battery - Click Randomizations Pop your favorite music in the computer's cd player, turn out the lights and enjoy. Ancient Hippie
lol. i prefer 'jakdaw' or 'oinksie' in Amarok. OSX iTunes has some cool ones too but nobody has $4!+ on jakdaw. i remember when i first saw the visualizations in WMP back in the first days of XP. i thought it was cool just short of the 3rd plateu.
http://www.nullsoft.com/free/milkdrop/ Very good stuff. However, there may be newer plugins than this. When I was into visualization though, this was the best out there.