ags and adga will interchange registries with each other ndga will register from adga or ags. idgr is the cheapest and will register noa nigerians and is the only registry that will. idgr will take adga and ags papers to register but adga and ags will not take idgr papers. adga is the most respected and has the most sanctioned shows at least in the northeast. however they can sometimes cop an attitude, so beware. so i guess if you want to show or sell show animals adga is your best bet. we double register ours with adga and ags. we also have started doing noa registrations with idgr for our grades. if you are just selling pets any registration will do. 4-h will also take idgr as well as adga and ags.