My parents have been married for almost 40 years... they at this point I don't think really like each other that much, but I think at the same time rely on each other heavily for everything. I still make an effort to talk to my parents at least once a week. Growing up, I had a decent relationship with my parents.... my older brother passed away before I was born, so I think that my parents always kind of resented me because he passed away.
My parents having 3 living children, and typically, 2 kids bond with the parents better and it leaves 1 kid not as close.
After college, I tried to patch up our relationship and it's amazing how once you've grown up, you can see a different prospective and understand where they came from on issues that you had. It allowed us to have a pretty good relationship for a few years until my one sister got into alot of issues with drugs. During the height of the drug isssues, my sister was able to convince my parents that I did alot of bad things and my parents have never quite trusted me fully ever since (and I was completely innocent on this whole thing). Because of this, I have not spoken to my sister in many years and has caused a permenant stake to be driven between my parents and I.
I still talk to them about once a week and see them at least once a month. My in-laws on the other hand, I can't get away from. Paula has said on multiple ocassions that her mother is her best friend and they do alot of things together.