This is one I use, and it is really really good, great price as well. 500watts is also more then enough for you! If you have a P4, it is P4 compliant as well. Here ya go!
WHY??? Antec is also good, but just because it is the most expensive doesn't mean a thing. How much do you want to spend?? I mean, you could get a whole new tower for some of the prices of the Antec and Thermaltake PSUs out there!