[Gusteau]

My maternal grandparents are Grandma and and Grampa, though when I was too young to pronounce that they were Mamaw and Pampaw. My maternal great-grandmother was Grandma FirstName.

My paternal grandfather was Papa FirstName, and was also called that by his great nieces and nephews if I remember correctly. My paternal grandmother died before I was born, but we have always referred to her conversationally by her nickname. My grandfather would always call her "your Grandma Nickname" when he talked about her.

As to preciousjeni's question, my sister and I have called our parents Mom and Dad since we grew out of Mommy and Daddy, although I'm not above the use of Mommy when the occasion calls for it (as in, I need my mommy). My mother and her siblings call their parents Ma and Dad.