Principal Network (Software) Engineer
Truthfully, it was my teachers more than my classes that inspired me. If you find a teacher that you like and learn from, take as many courses as you can from him/her.
In my school career, though, two courses stand out: Database Design Principles and Software Application Development. In Database Design, I learned the theory behind designing good databases and how to "normalize" them. It didn't deal much with SQL or any specific vendor's database, but rather what makes an efficient database design.
Software Application Development was a practical class in which we came up with a program concept and wrote the program. The only criteria were we had to put at least 80 hours into the project, and it should compile and run (even if unfinished.) Making a full-fledged, "customer-ready" program taught me so much more than the little command-line programming exercises we'd often do in class.