I second newegg. I stopped using tigerdirect when they took over com usa, and I now have to pay state taxes on my orders.
i always hear people complain about tigerdirect and i don't know why. i've always had excellent transactions with them. i know their prices might be slightly higher then newegg, but in my opinion they have a great selection of components, and their return procedure and support is excellent. but to each his own, i suppose. another good site is pricewatch.com. it will search dozens of websites and find the cheapest price for what you are looking for.