I called my maternal grandparents Mama and Daddy, I lived with them until I was 2 so it made sense. Paternal grandparents were Grandpop and Grandmom which I later changed to Gram.
My kids called both grandmothers Grandmom and my dad was Grandpop.
My grandkids have normal and unique names for us. My parents are Big Pop and Big Grandmom. They call their other great-grandmother GG. The other grandparents are Mom Mom and Pop Pop or Grammy and Poppy. My DH is Poppy and I get Grandmom or Memoo or Memaw from my one grandson. He is 3 and has just started talking, he has a hearing problem. I have a feeling that Memoo will stick.