If you are looking to go beyond using traditional, arguably misleading, definitions of entropy involving “disorder” and “messy bedroom” analogies, the Boltzmann Bucks game fits the bill. The game, pulled from a Journal of Chemical Education article, provides a wonderful opportunity for students to more accurately conceptualize entropy.
You are likely aware that diamonds are converted - albeit slowly - to graphite under normal conditions. Thus, diamonds don't last forever, in contrast to the popular advertising slogan. However, did you know that you can use chemistry to prove that diamonds are not forever? It's simpler than you think...
I was recently drawn to an article published ASAP in JCE entitled Application of the Second Law of Thermodynamics To Explain the Working of Toys. Erick Castellon wrote the article highlighting the use of three toys that are used to help students develop an understanding of the second law of thermodynamics and entropy by having them observe the working of the toys and the energy transfers that occur while playing with them. I already had two of the toys, the radiometer and the drinking bird. I ordered the stirling engine from the link provided in the supporting information. As I waited for the stirling engine to arrive from Japan (which was only a few days) I attempted to write an activity to guide my students to conceptual understanding as they worked with the toys.