I have all sorts of semi-ridiculous file folder names on my desktop like "Time Travel" and "Batcave Blueprints" so when I share my screen it makes people attending my webinars feel at ease and that it is okay to smile. 
I started my Muppets collection for a similar reason. It sits in my office just to  bring joy to me and others who see it - And I think that is a huge part of the collecting experience. 
What collections bring joy to your office spaces?