I, too, use Winamp. Can we get a side-by-side comparison in here of both media players? I'm pretty interested in foobar2000, but I'm already comfortable with Winamp.
Foobar2000 can play almost everything and has a lot of conversion and customization options, more so than Winamp. It's also not as bloated. Even with hundreds of tracks loaded in dozens of playlist tabs, fb2k doesn't show any signs of slowing down at all. Besides, it was made by a former Nullsoft employee, so you can think of it as the spiritual successor to pre-AOL Winamp.
I love foobar because I can add a plugin to remote control via iOS, as well as the intense customization of the interface. I do use MOC on linux though.