Mac-11.info - "#1 Central Resource on the MAC-11 family of weapons, accessories, & clones."
Page's Anime Do's and Don't's - A guideline on how to be a pleasant otaku. In order to combat the stigma against otakus, we first must address inner problems like managing our interests and how we share them.
Depop - Secondhand market for gullible rich children and scalpers, but can be great if you know what you're looking for.
cdjapan.co.jp - Several Harajuku brands (Deorart, Sex Pot Revenge, Maxicimam, Listen Flavor...) sold internationally.
Wunderwelt - Second-hand market & retailer for J-fashion.
Hard Jewelry - Personal favorite pendant is "Pinhead Larry."