I'm still in school, so I know that I don't quite fit into this question (I don't have any real experience to back up my choice). Howeer, I would have to say the Intro to Java course I took. I'm not a CS major because I thought that the only people who could be CS majors were the ones who had been programming FORTRAN since they were in Middle School. However, this course showed me that people trying to get into programming often know a lot less about computers than I do.

So while I might not ever get a job programming (although I'm *very* sersiouly considering going for a Masters in CS), it has become kind of my passion as I slowly experiment with different languages.