The Zalman 7000 series is worth checking out. Various flavors are available including all copper and hybrid copper/aluminum models. Really easy to install for P4 setups and also are kinda universal so you can keep the cooler if you change to other CPU types. They perform well, are quiet and look kinda snazzy.
All Zalman has to do now is to put an LED lit fan with clear blades in it to dress it up a bit. You heard it here first, Zalman. Please send me royalty checks, heh.