Greninja, Shulk, and Lucario
One of the worst things Nintendo ever did in terms of exacerbating the amiibo situation is make so many retailer-exclusive deals in North America. While everyone all over the world could find any amiibo in any location, the US and Canada often had to hunt at certain stores that only had a paltry few figures in stock, sometimes at multiple spots on the same day. In short, unless you had a spouse or friend who hunted for you, it was nearly impossible to get everything.
This issue is much less important now due to a higher stock allotment (Bowser Jr. was well stocked at many Toys”R”Us locations for at least a few days), and now, you may be able to get a few ones you missed out on. It has come to the forefront that Best Buy has a listing for Shulk, Greninja, and Lucario, indicating that these releases may have just been timed. It’s not 100% certain right now, but reliable sources are pointing to the fact that this will likely happen.
Shulk, Greninja, and Lucario show up in Best Buy system [reddit]