for shoes, there is not a single place better than
www.zappos.com
In fact, I think they are my favorite online seller, above even newegg. I ordered a pair of shoes recently, and they were upgraded to 2nd day air for free.(I had picked the free option, 4-5 day shipping.) When they arrived, there were a few small defects on one of the shoes. I called up customer service, and they gave me a UPS shipping label and shipped out a new pair immediatly. The exchange pair arrived 18 hours after I called them. Amazing customer service.
Also, as I saw previously suggested, always do a quick check of the website at
www.resellerratings.com and make sure they're a decent company.