I have taken some of the following courses myself, but there are a few I have yet to conquer. In that vein, I have been in touch with students who have completed these courses in order to get their best recommendations. Here goes:
Federal Courts: Without exception, Federal Jurisdiction (Introduction to Law Series) by Erwin Chemerinsky has unequivocally been the most ubiquitous supplement recommendation I have received from most students who have taken this course. However, I have yet to take Federal Courts, so I cannot speak on its merits from my own experience.
Antitrust Law: I have taken antitrust, but will have to admit that buying a good, comprehensive supplement for it is quite tricky--principally because the law is not very concrete. Thus, my recommendation splits two ways. First, if you just want a quick summary of the current case law and a brief explanation of underlying, basic economic principles embodied in the law, try the Antitrust Law and Economics Nutshell by Ernest Gellhorn, et al. If you have a little more time to explore the nuances of prominent cases, check out the Hornbook on the Law of Antitrust by Lawrence Sullivan and Warren Grimes.
Conflict of Laws: I have searched the internet for recommendations on a supplement for this class, but there does not seem to be a dominantly suggested one. The one supplement that seems to get consistent praise is Conflict of Laws (Introduction to Law Series) by Lea Brilmayer.
Administrative Law: Examples and Explanations by William Funk and Richard Seamon--hands down.
Remedies: I am told the Examples and Explanations by Richard Hasen is the best supplement for Remedies. The Remedies Nutshell by William Tabb and Elaine Shoben is also very helpful.
Immigration Law: Depending on your teacher, some supplements can certainly be better than others. There is not, however, a great selection in the aggregate. I found the Immigration Law and Procedure Nutshell by David Weissbrodt and Laura Danielson extremely helpful, but it focused more on the constitutional aspects of immigration law than on the nuances of the Immigration and Nationality Act and its application. That said, I cannot imagine a supplement going into too much detail about a statute as complicated and as long as the INA.
Criminal Procedure: I, like Craig, love Joshua Dressler's work in the criminal law arena in general. I used his and Alan Michaels' Understanding Criminal Procedure (Investigation) as a supplement, and read it front to back. It was very helpful.
Corporations: Everyone's favorite course, no? I have heard mixed reviews on a number of (potentially helpful?) supplements. First, Corporations (Introduction to Law Series) by James Cox and Thomas Hazen has been adamantly praised by some, but criticized by others for oversimplifying the Delaware General Corporation law--but this may be moot if your teacher does not emphasize it too much. I have also heard that Examples and Explanations by Alan Palmiter is a fantastic reference.
Securities Regulation: A lot of people with whom I have spoken love the Examples and Explanations by Alan Palmiter, but some suggested that the examples are too short.
Federal Income Tax: The Examples and Explanations by Joseph Bankman, et al. has been given resounding praise from those I know who have taken the course.
Evidence: There are numerous fantastic supplements for this course. Among the many suggestions I received are Understanding Evidence by Paul Giannelli and McCormick on Evidence (Hornbook Series) by George Dix, et al. For practice, Siegal's Evidence: Essay and Multiple Choice Questions and Answers was highly recommended.
I hope these recommendations were moderately helpful. If nothing else, they should at least provide for a decent starting point when you begin preparing for exams. The tip line is always open for more requests and, in the words of Craig Reiser, 'happy shopping!'