Iconspedia is one of the best resources available online for free icons and graphics. Although they allow users to submit graphics to their collection, they filter through the submissions meticulously ensuring that only the best graphics get listed.
Their collection covers an extremely wide range of topics. They have icons for nearly every possible purpose. This is one of the largest collections of top-quality icons that you will find. Browse through their galleries for a few minutes and I’m sure that you’ll find something useful.