I got really lucky with my transfer courses.  Even though I transferred twice - once leaving Pitt and a second time to return (!) I didn't lose any courses.  One reason was that my grades were good - all A's and B's.  Another was that I stuck with the basics:  courses that are offered everywhere like Micro and Macroeconomics, Shakespeare, Intro to Psychology, Principles of Accounting, you get the idea.  My advice if you think you're going to transfer, is stay away from the exotic course offerings and stick with the ones that everyone recognizes.