I've taken many college courses and a few of them will never come in handy, or they might come in handy for a one-time conversation with a stranger on a flight. But there are some courses that might not be major-related, that every human being should have some experience and knowledge in.
Our bodies are ours until death do us apart, literally. To say the least, we should know the basics about why our bodies develop and react the way they do. You don't have to be a Nurse or Doctor to understand your body. Just like every vehicle has a manual, we should have one too.
This course comes in handy on a daily basis. We should know what we eat and eat with purpose (for the most part). The more knowledge we have about what we eat, the wiser and healthier our daily choices.
Interesting Writing Course
The University curriculum offers a basic checklist for writing and English courses a person needs to take. I believe everyone should invest some time in taking an extra writing course that will sharpen their writing skills, an extra step beyond what the required courses have to teach.
News constantly unfolds around us, especially in this day and age where information comes in nonstop from all directions. It's important to take some sort of journalism course, not necessarily a writing one, to process and organize news information in a way that makes sense while weeding out the fake news.
You don't have to be a scientist to understand some basics about the cosmos. I believe it's important because humans are shifting focus into space and discovering new ways to make life possible outside of Earth. Perhaps living in space will not occur until after my generation, but there will be plenty of building blocks coming up, so it's nice to have basic knowledge on what the future will hold.
Chances are you will have close interactions with a child, whether it's yours or it's your sibling's, or someone you see very often. It's important to understand children's development and psychology, even on a basic level so that we can help children develop into stronger human beings. One course will not make you a child therapist, but it will definitely help with understanding them better.
Coding, or something like it
I'm the least tech-savvy person I know, trust me when I say a coding course or computer skills course really helps. Computers are everywhere and they're not going away in the foreseeable future. Just take the time to nudge yourself into a better relationship with them.
Something that scares you
This last course could be anything that you think you might not do well in. If you have some wiggle room with your course load or with your GPA, I think tackling a subject you might fear can teach you something. You will either realize you're way better than you believed, or you might have accepted a challenge and realized you were correct all along. The most important thing is to try something new and you might pleasantly surprise yourself, or you will have a definite answer. Either way, it will help you overcome that fear and make you feel like an improved person at the end of it.