Needs to be intelligent, responsible, sense of humor, sense of self, awareness of othes, respect for others and himself, love of his mother/father, be able to communicate. Physically speaking, must respect his own body, (for me) must have some shape & discipline in his maintenance of his body, habits & hygiene. As far as ups & downs, be able to discuss issues, share in decisions, be open to interesting / creative solutions, agree to disagree when appropriate & not carry grudges. Revel in the good times, appreciate & learn from the bad times and remember them relative to the good times.
Also helps if he has a job, meets his obligations, has his own house (i.e. doesn't live w/ parents or weird pothead friend from college) has his own car w/ air conditioning (i.e. doesn't want to drive mine). Also appreciated if he keeps a well-maintained lawn "down below".