Nonna or Noni would be a most common, from my limited experience with Italian friends.

I'm Italian-American. :-)

Nonna is Grandmother

Nonno is Grandfather

Nonni is Grandparents

Nipote is Granddaughter and/or Grandson

Zia is Aunt

Zio is Uncle

My ex's grandparents were both first generation Italians. Gram'ma was the preferred term at their house. (Emphasis on the Gram part. (Us Southerners say Grandmaw! LOL)

We called our grandmother Mama, and grandfather Nonno.

We're 3rd generation Italians with our families coming from Italy and Sicily. We call our grandmothers Nana and our grandfathers Nano.

I'm Italian/American and my grandmother was Noni. (no first name added)

Thanks, everyone! I'll just change Nana to Nonna. Perfect!

My mother was Italian and Nonna is what we call grandmas.

I don't know about Italians, but we Germans called our Grandparents Oma and Opa. My friend Patty (ethnicity unknown) caled her Grandmother "Nanny."

My nieces and nephew call their Italian grandma Nonna.

FWIW, Lidia Bastianich on her shows always refers to herself as Nonna (Nona?) when she's talking to her grandkids.

I'm Italian and grew up in an all Italian neighborhood. We called our great grandmother and grandmother, Nana and grandfathers Nano. Our nieghbors and friends did the same in their families. My kids call my parents Nana and Nano.

Hallmark and other greeting card companies use Nana.

I don't think there is an absolute here, each family is different, so you can't go wrong with either one.

My children called their 2 Grandmothers "Grandma Josie" and "Grandma Wood." My husband's mother was named Josephine/Josie and Wood is my maiden name. Every family is different.

Know this isn't what you asked, but we're German Americans and my grandmother and great grandmother were both Nanny. I would love to be Nanny to my gk, if I ever get any--LOL.

As someone else said--you won't be wrong, no matter what you decide because there's really no universal answer to this one, families all have their own traditions.