An odd place to post this, but I'll bite.
1. Similar sense of humor to mine (any sense of humor is good but if we match its even better).
2. Confidence and assertiveness (confidence to be assertive).
3. Being able to communicate with me (tell me when something's wrong, when they want something, etc.)
4. Ability to have intellectual conversations
5. A strong sense of privacy. So that the deeper parts of our relationship aren't the talk of the town next time we get in a fight.
Honorable mentions are a high *** drive and strong desire for intimacy.