This is a tough one. I sometimes regret choosing to go to college, but it truly changed everything for me. I studied Materials Engineering, and now I'm doing a web startup, but I really believe the college experience, the connections I've made, and the failure in multiple ways in college (not in classes thankfully) has helped me prepare to take the leap to full time entrepreneur.
Yup... if I knew then what I knew now (a moot point, admittedly), I'd audit classes or do the cheapest possible thing to be associated with the university without paying for it, and simultaneously work on startups/projects.
I wouldn't say it is the classes though. College transformed me as a person and forced me to grow up. Maybe it helps that I go to Drexel where we have co-op (school for 6 months, work for 6 months, repeat). Anyway, I would not have been prepared to lead a start up right out of high school. Today, I think I'm ready.