When they were alive, my grandparents on my dad's side were Nana and Pop pop/Paw Paw... I never met my other grandparents because they lived in Indonesia, but I'm probably heading to Bali this Winter.
my sole grandparent i call frank. i don't see him that often though, but whenever i do we usually sit around and drink whiskey and smoke cigarettes. you can tell he's bombed whenever he starts quoting JFK (he's from Montana).
I call my mom's mom Grandma and my mom's dad Pompom (my brother started calling him that, I have no clue what the reason behind it is) I call my dads mom Grammy and I called his dad Grampy before he died.
on my moms side grandparents: MiMi & Paulpaul Great grandparents: Nanny & Gan-gan dads side: Paulpaul Buckley
grandpapah/grandmamah or vovo and papai (used to be papah but i changed it after i was like. 3.) and when speaking of someone else's..i call grandpapahs pepe