I live in a tiny house so I tend to avoid collecting stuff. I do have a really impressive collection of dog hair, however! :P
I do buy a cheesy magnet from anywhere I travel and those are all on my fridge. I like seeing them every day to remind me of fun times.
I also have an alarming number of quilt patterns. I tend to see one in a magazine I like and pick it up. I did start removing the patterns I want, slip them in sheet protectors and store them in binders. I was able to get a big box of magazines into two good sized binders.