Keepsakes vs. stuff??

It's been four years but we are finally cleaning out my grandma and grandpa's house so that my cousin and her husband can live there. My parents have been working hard on getting most things out and sorted and my sister and I spent a day at the house a few weeks ago and almost all day on Thanksgiving going through more stuff. It's caused me to stop and ponder the nostalgic value of things vs. it being just stuff.
I am a collector, but only of stuff that I love, or that makes me feel good, or has a memory attached to it. I love to have "my things" around me, it provides comfort and makes a cozy happy home for me. But going through Grandma's stuff you begin to wonder if there is any point in keeping it, it's just going to sit somewhere where we can look at it and say, hey, that was grandma's!
My mom and dad kept a lot of the furniture and other things that have value, whether just sentimental, historical or monetary. Eventually that stuff (however morbid it is to think about) will be passed to my sister and I, and eventually to our future generations. Will it retain it's value as it's passed down? Will my grandchildren wonder why the heck I kept a blue vase or a ceramic cow that was hers? When does it all cease to be special, when you have a houseful of stuff you can't get rid of because it belonged to someone you care about? Does it really help to keep their memory alive?
I'm somewhat torn about this because I also feel like we (society in general) have too much crap. We buy buy buy and clog up the landfills with a bunch of useless crap. Don't even get me started on black Friday and the sheer volume of shit that people buy just so they can give a gift to someone that has no sentimental value.  Wow, that was a bit of a tangent...
I'm not sure what the point of this post is... I'm just thinking outloud really. It really does make me happy to have my grandma's things around me, I just worry that maybe it's too much...