Ask HN: What "useless" classes should I take?

As a biochemistry major and math/cs minor, I feel like I've taken a fair share of classes that will be directly applicable to my career as a physician-researcher. I am in the lucky situation of being largely finished with required courses, with one year left to go. I want to spend this year branching out of my comfort zone and taking classes purely out of interest, with no concern about whether or not it will directly impart me with skills I will need. What kinds of courses would you consider to be most fulfilling?