Somehow this thread escaped my notice up to now.
We have to be able to talk. That's really paramount for me. We need to be able to have engaging conversations.
We need to be sexually compatible. Our sexual passions need to be complimantary. She needs to be willing to experiment and try new things. She needs to respect my boundaries, and she needs to be willing to put aside judgements.
She needs to be independant. If she expects me to spend a ton of time with her every day, it'll never work. She needs her own passions and interests. She needs to know that our relationship is not as important as our individuality.
She needs to be supportive. She needs to be there when I need her, she needs to be reliable. I need her to care about my pursuits, and help me to achieve my goals.
She needs to know that I don't do the standard set of relationship agreements. I'm not monogamous, and I don't make promises about 'forever.'
It helps if she gets my sense of humor, and any hobbies we share are also a bonus.
Of course, anything I expect of her, I also expect of myself.