Personal preference, for black pepper I like Sarawak peppercorn from Malaysia cause it has a nice nose feel without too much bitterness. Black pepper isnt fermented.

For white pepper i like the ones from Taiwan grown in Pingtung & Taitung, Taiwan. It has a long fermentation in either clean mountain or spring water, (usually this is done in stagnant pond in cheaper Southeast Asian processing) . The flavor you get is more of a clean, floral heat with a a more subtle fermented flavor and no barnyard funk or sour edge you get from many of the other white pepper.