Honestly, I can't say enough good things about Zavvi. I've been a customer for a few years now, and their service has always been first rate. Everything I've ordered from them has arrived in great condition, securely packaged and on time (sometimes much faster than expected). Their website is clear and easy to navigate, and their updates on orders are timely and concise, without spamming me with unnecessary information.
I suspect I'll be a customer of theirs for many years to come.