Beloved is taught in any number of literature programs; I doubt you can go wrong there (Sister Francis aside!). The characters in Song of Solomon are unforgettable; if you like magical realism, "Song of Solomon" has it.
Those are the two I remember best although, honestly, I don't think you can go wrong with "Jazz" or "Sula" - basically, if it has her name on it, it's probably worth reading.
Great. Five re-reads on my list at once, dammit! And it looks like she has a new one coming out this fall.
