Perennial "Roman Chamomile" (Chamaemelum nobile) gets along well with (and can even hold its' own with) different mints (including lemon balm, bee balm, hyssop, germander, horehound) and I let the annual "German Chamomile" (Matricaria recutita) type self-seed around my beds along with buckwheat, daikon radish, and red russian kale.