I have one non-negotiable.... Spirituality. You must be open-minded, open-hearted and interested in alternative faiths and spiritual practices at least to the point of being willing to discuss/debate philosophical differences and participate in rituals, etc. on special occasions.
And then one solid, undeniable truth... I'm a Sagittarius. The wild wanderings -- verbal, mental, emotional, physical, sensual and metaphysical -- of a Jupiter's child can be tiring. If you have days where you don't have the energy to get off the couch, then you do not have the energy for me.