I'm assuming you've cloned whatever you want to keep already?
What Shaymin do you have? I think the one I have is Oblivia. I'm curious which Rayquaza you have as well as there was a nice Event one out with V-create learned (cannot be learned except via Events, and so far Rayquaza and Victini each have one). Also wondering about Deoxys; again, I have an Oblivia one. I have two Jirachi now, and Celebi is considerable because mine's been used in the Castelia City bit (making it useless for trades as it can't be used).