WinAMP 2.09 works great for me - just make sure you tell the program that the CPU supports MMX. Light on CPU usage; the newer a program gets, the more bloated it gets.
Fullscreen visualizations? If you're in a car, that's the last thing you want!
(There was a fullscreen user interface plugin for WinAMP, but I never got it working - pretty buggy. It's impossible to find on winamp.com, now that it's loaded up with 3 million "d00d i gotz sk1nz" skins and another 3 million aol.com ads... sigh...)