This thread, while a little out of date is a fairly comprehensive list of e-retailers here and abroad.
I'd add, ToybotImportz, Thelittletoycompany, robotoys, xavierscollectables and take off TFI downunder and Premium Collectables, both failed.

Otherwise, this section has a pretty good list of stores via the feedback threads.

some Kmarts appear to be getting the Brunt wave in if you are of the physical retailer bent.