Fun question!
Definitely too much paper and I am an all digital guy - still too much paper. Not just books/magazines but file folders of medical records, old taxes, etc... Too much paper! Mostly stuff that I am too lazy to spend hours and hours scanning.
Also, too many dishes and silverware - it just feels wrong to split up sets. For some reason, people like to give me coffee cups and I hate tossing them out. I need to learn how to re-give them away.
Sometimes it feels like I have too many spare parts but then I need one and am happy I have them.