For each class of course.

You see I am a 50 glad, and of course blindly went for all Vit/enmity/hp materia, and ended up realizing that not all pieces can get say vit or hp sadly. Adding a professional materia set to a full thing of say, 49 cobalt gear, has become alot more tricky then I thought.
What are your thoughts, of must materias, for all classes. Please remember to be realistic with the materia and where it can be put on ^.^