My mom’s parents were Grammy and Grampy. My Dad’s mom died before I was born, and my dad’s father didn’t think having a relationship with his grandchildren was valuable, so I didn’t call him anything.
I miss having grandparents, especially when my friends mention theirs 
Delphica, Na-Na is pronounced like Nah-Nah, isn’t it? I’ve heard others say it that way.
mom’s side - grandma and grandpa
dad’s side - mommom and poppop
when she was a live, my great-grandmother on my dad’s side was grandmommom.
Mom’s parents = Ummie (grandma) and Ubbie(grandpa). Bastardized Ami and Afi, which is Icelandic.
Dad’s parents = Grandpa & Grandma
Step-dad’s mother - Grandma Ruth
Of course, I don’t call any of them anything anymore, except for my dad’s mom.
My mom’s parents were Grandma and Grandpa. My dad’s parent’s were largely unknown to us. When we met them, we called them Grandfather and by her first name as she was a step grandparent and she was introduced to us by her first name.
My mother is Nana to her grandkids and my father has only been around my kids once where he was introduced as “your grandfather” the children choose to call him “Grandad” with his common name appended.
My children’s other grand parent’s where named by older cousins long before my kids came along. They are known as Memaw an Papaw. (For the record, they are not from Appalachia.)
LOL good grief, when it’s written out that way – Nah-Nah – it sounds like we’re taunting her. But yes, that is how we say it. 
I called my maternal grandparents “Pa and Ba.” I’m not sure why; the origins of this have been discussed within my family in the past, but not for a long time, and now I’ve forgotten them. But everyone, regardless of the generation, always called them that.
Maternal: Nan and Pop (or Nanny and Poppy)
Paternal: Grandma and Grandfather.
I’m not the oldest grandchild on either side, so both these names were set up by my oldest cousins. I’m not sure why we have Grandma and Grandfather, but this is what we’ve always called them. An Aunt-By-Marriage decided that it didn’t make sense, and had her children call them Grandma and Grandpa. The rest of us ignored her.
People give me weird looks when I talk about Poppy, and usually ask “Who??” when I mention Nanny, so I refer to them all as “My Grandmother” or “My Grandfather” when speaking of them these days.
Paternal: Grammy and Grampy, later Grammy Rachel and Grampy Joe.
Maternal: Papa. My maternal grandmother died before I was born. Some of my other family members spell it “Poppa” but they are misguided.
Maternal: My mom’s dad died when I was a year old, but we probably would have called him “Daddy Ted,” because my mom and her brother’s called their grandfather “Daddy Paul.” Mom’s mom was just “Grandma.”
Paternal: “Grandma” again, although one of my cousins always called her “Hi.” My dad’s dad we called “Grandad” or “Grandaddy.” He didn’t like “Grandpa” so we never called him that.
Paternal: Grandma (Family name) and Grandpa (Family name). They were formal, religious fundamentalist types. Plymouth Bretheren to be precise.
Maternal: Nanny and Popeye. And, by god, I miss them and I wish they’d lived long enough to meet my daughter and undermine her training and discipline. They were larrikins the pair of them.
I call my grandparents ‘Grandma’ and ‘Grandpa’. Except in the case of my grandmother on my Mom’s side, I usually call her ‘Dead’.
Mother’s side: Nan/Nanny and Gramps. Nan’s still alive, but Gramps died 11 years ago. He was a truly excellent man, and we were the best of friends when I was small. I still miss him.
Father’s side: Grandma (Grandfather died before I was born)
I only had one living grandparent by the time I was born, and she was always called Granny. Everyone called her that. It was like she adopted the world.
Mom’s side - Gram
Dad’s side - Mema
both grandfather died before I was born.
okie, I’m a sad boy now, cos my Gramps died back in February (funerals make great Valentine’s gifts!). Anyhoo, he wouldn’t want that, cos he was a jocular kinda guy. So…
Maternal G’father:‘Gramps’-cos he’s from the U.S.of A. (and despite being dead, I’m not gonna use the past tense, just cos! Damn, there go the tears!). Maternal G’mother:‘Jig’ -cos when she was 6months old she would dance, hence the nickname. Everyone, army friends included, still call her that!
Paternal G’father:‘Grampa’. Paternal Grandmother: ‘Grandma’.
-(yes, boring)
Mrs Dangergene’s Paternal grandparents (she never knew her maternals) were grandfather: ‘AhKong’ grandmother: ‘Ahmah’. These being good Hokkien titles for one’s grandparents.
Dunno what my parents will be called when the Li’l Dangers come along, but her parents will get the traditional ‘AhKong’ and ‘AhMah’ (and no playing with that!).
Danger Gene
(who misses his Gramps!)
I never knew any of my grandfathers and I only know my maternal grandmother. I always called her “Abue” or “Abuelita”.
Paternal Grandparents - Bapa and Nana
Maternal Grandparents - Grampaw and Mimi
Maternal Great-Grandmother - Gummo
All of the unusual names were given by my oldest sister except Gummo, which was coined by my mother.
All of my grandparents were Polish. Mom’s parents were Busi (pronounced “bushy”) and Dziadzi (pronounced “JAH-gee”), and Dad’s parents were The Other Busi and The Other Dziadzi. Dad’s parents never learned to speak English beyond a few phrases, so we never got to know them well - plus they were a lot older than Mom’s folks, so we never developed the close relationship with them that we did with the younger grandparents.
My daughter and my sister’s kids called their great grandparents Busi Julie and Dziadzi Frank, and my parents were Busi Chick and Dziadzi Ted - but now that my grandparents are dead, it’s just Busi and Dziadzi. And my daughter calls her other grandparents Gramma and Grampa.