I really didn't see my grandparents on either side of the family very much. Dad's parents were deceased before I was born. He grew up in a foster home (when foster home meant a bed, some food and a lot of work). but was lucky to be in a loving Foster home. He adored his foster parents; his foster mother was alive for most of my childhood, we just MN, we lived in NJ, so not too much interaction there. It was always Grandma and Grandpa for both sets of grandparents.
All my kids called my Mom "Grammy"; my dad was deceased by the time my kids were born. Two of the kids from my first marriage used Grandma and Grandpa for their paternal grandparents, but after a while, their paternal grandparents lost interest. DH and I have a child together, my mom was Grammy to her, as well. DHs parents were Grandma and Grandpa to all the kids.
I have to say that having blended families makes this kind of thing take more time than it should!
Oh, yeah. Our grandkids call us "Oma" and"Pop-PoP". Best names we've ever been called, best job ever. Trained for it my whole life!