XSPC online store is one of the best that I've seen to date. It's clean, well organized and doesn't take forever to load. Haven't had the pleasure to order from there as of yet, though.
On a sidenote I really wish they'd do nickel plated versions of their CPU/GPU blocks. Just personally don't like the copper finish that much. With Raystorm it doesn't really matter as you can't see it underneath, but with the GPU blocks... I just feel it makes them look 'cheaper' for some reason.