Ahhh, what a can of worms to open
We live next door to husband's parents, so that makes it all the more interesting. We had an excellent relationship while dating and engaged for 2 1/2 years. My parents were separated at the time and they became my family. Once married, boundaries were a little vague, MIL was pretty bossy, and they pretty much just walked in our house whenever they wanted. Still, it was very good between us, although I would get frustrated. When DH was gone, I'd go to their place and just sit and talk with them.
Things fell apart when DS was born. I think they had unspoken expectations of grandparenting, and we had our own expectations of parenting. They were very dissimilar, and I feel badly about it now. MIL was still quite bossy, only now it was really personal as it had to do with my mothering, not just my housekeeping. I was constantly irritated, offended and defensive. I coped by avoiding them as much as possible. I believe it hurt them deeply to have relatively little contact with our DS (but I didn't really "get" this until much later). DH spoke to them once about their constant disrespect of our wishes when they were spending time with DS, and MIL was gravely offended and hurt.
It took years to get back to even basic courtesy, as MIL wouldn't even greet me in public, and I even once overheard her sharply criticizing me to the other sisters and brothers in law. Anyway, it has slowly gotten better over time.
We now have a courteous and kind relationship, and they enjoy our kids (although infrequently), but it probably will never be a close friendship. It's just very polite and superficially friendly.
My husband, OTOH, is adored by my parents. They are more concerned if he is happy when visiting than me

Mom makes his favorite foods (as well as for the other inlaws), dad wants to do things he enjoys. And we live 1 1/2 hours away, so if he's not happy with them, there's something wrong with him!