Well, I mean a good stylised set of controls for the common transport functions - play, pause, stop, ff, rew, skip fwd, skip back, eject. That kind of thing. Another icon that is often MIA is lights. So far I've managed to scavenge a couple of colored lightswitch icons from a Prontopro screen but, again, it would be nice to continue a common theme across the entire set of icons.
Most of the customised ones I've seen so far leave out at least one or two. So unless you're graphically talented (I don't qualify
) it's hard to carry the theme on to these icons.