The most important part of Winamp is the global keyboard shortcuts you can set up. I have been using wasd controls for my games and my player since forever. Well, since I found the global keyboard shortcuts in winamp...
wasd for games, ctrl+shift+qewasd for play/pause/forward/backward/next/prev and so on. Don't need to switch window, don't need to move hand away from wasd. Can't live without it now even though I don't have so much playtime any more. Works just as well in any other environment.