The best interdisciplinary courses are going to depend a great deal upon the subject area you have chosen and what other fields can effectively cross over with it. If you are an English major, for example, there may be few classes that include both language arts and work in chemistry. On the other hand, if you are focusing on psychology, but you are interested in how surgery impacts people psychologically, then you may be able to choose a program in psychobiology. Any interdisciplinary courses you attend should meet the requirements of your college, so that they count toward your graduation.
Since interdisciplinary courses are those in which two different disciplines are brought together, look for fields that may naturally lend themselves to such combinations. Your focus or "major" in college can have a tremendous impact on the types of opportunities that will be available to you in these classes. Some subjects, such as biology or law, may naturally lend themselves toward a curriculum that includes other fields of research and work. If you are majoring in law, for example, then look for interdisciplinary courses that go into greater detail in a category like entertainment contracts then a standard law class might.
As you consider different interdisciplinary courses, try to find subjects that include collaborative instruction from professors in multiple fields. These types of classes can be rare, but exposure to multiple ideas from two instructors provides you with a rewarding and valuable experience. If you are interested in interdisciplinary courses in entertainment contract law, for example, then look for classes taught by a law professor and a film teacher working together in the classroom. Other programs may be presented effectively by a single instructor who also focused on multiple disciplines as a student, and these classes can give you insight into how you might take your studies further.
One important consideration to keep in mind, however, is how any interdisciplinary courses you take can help you toward graduation. Unless you are looking for elective classes that do not have specific requirements, try to find courses that count toward the credits you need. You may need to consult with your advisor or someone within your college to be sure that you can attend such classes and have them take the place of a different course. Some schools offer a degree in a particular interdisciplinary program, which you may want to consider if you find that one field does not properly represent your interests in a subject.