I agree with one of the above, something along the lines of philosophy, or law/contracts, or english writing, etc. the subject matter is actually less important then the process you'll be learning. Basically, how arguments are constructed and how to reason and think critically. Very practical. I personally found a course on human sexuality also very fascinating. if it's available - I took a course along the lines of career management, covering everything from resumes and interviews, to (and most importantly) how to manage your career, deal with bosses, coworkers, etc. Most of university is 80-20. You'll forget a lot of the knowledge but remember the process. A few things'll stick out and you'll use them again and again but most stuff you'll jsut forget.