I love POGS. My older daughter got rid of a ton when she got married and moved out--and I gathered them up. They are one of my little granddaughters' favorite toys. They stack them, sort them, count them and their favorite is getting into a laundry basket and having them poured over the top of the for a POG shower.
Strange but true, sometimes the simplest toys. I also bought a ton of them off of Ebay. Rare? I have no idea.