I look for people who are good listeners, able to talk about a variety of subjects beneath the surface, people who are loyal, not flakey, and are easygoing.
I look for not one quality but many, although I'm content with just a few. Honesty, openness, depth, good will and warmth probably come first. It's easier if we share at least some values and interests in common. I also greatly appreciate someone who is highly articulate, intelligent, free thinking and creative.