zipzoomfly may save you a couple dollars, but their service is shaky at best. Getting orders to you quickly, they do just fine. Getting orders to you correctly, and fixing the problem when they don't ... ? Well ... lets just say it took them 3 months to admit they never sent me a video card and to refund my money.
I've never had a problem with newegg's service. One time, they didnt ship out an order for like a week for some reason. When I called them to find out why it still hadn't been shipped, they were quick to get it packed and shipped that day, removed shipping charges and gave me free shipping for my next 2 orders. I'm saving them for really big orders I've got lined up.
Wombat is correct in that it isnt about cool website layouts. But you got to admit that zipzoomfly's site is kind of bland. lol Which may or may not reflect how "gung-ho" their customer service is in serving their customers.