Buy.com

Although, I like internet superstores for their abundance of merchandise and generally good prices, this one is a bit cluttered with ads.  It’s kind of nuts and somewhat distracting.  I can tell they're able to offer low prices by subsidizing their profits with advertising, but I suppose that's the tradeoff.  It’s not a terrible one, however, as I was able to find many models of headphones at really good prices.  For Grado SR-125s, I couldn’t find anything cheaper.  For Sennheiser HD-555, there was a place that sold them cheaper, but Buy.com was the one that told me about it.  I was also able to find hundreds of headphones, from portable to noise canceling, etc., but I wasn't able to find some of my favorite Sony models or anything too extravagant.

Buy.com has a price guarantee that applies to a select number of internet retailers.  If you find a better price at one of the eligible stores, you may be able to get the price matched.  They have free shipping on hundreds of thousands of items for orders over $25, but returns must be authorized within fourteen days. In terms of customer service, they have an extensive list of common questions and an email contact link.  Buy.tv is a section of the site that features videos about specific products which can be helpful, but it's basically more advertising. Take it as you will.  They even have a music video for their phone number.

Buy.com is massive and therefore, it’s a good place to find almost anything you want.  If you don’t mind being in the middle of an advertising circus, Buy.com is definitely an awesome place to find a good price on headphones or anything else you might need.