There are several qualities that make a good relationship: Communication, Affection, Compassion/Forgiveness, Honesty, Acceptance, Dependability, Sense of humor, Romance, Patience, and Freedom.
Some of the traits that are most destructive to a relationship are: Lack of communication, Selfishness/Unforgiving, Dishonesty, Jealousy, Lack of trust, Perfectionism, Lack of flexibility, Lack of understanding, Lack of respect, and Apathy.