Sense of humor.
Talkative, but not annoying. I love talking to the people I'm close to.
Give me space.
Something to do together, shared hobby, go out places, whatever.
Complicated (in a bad way).
Plays head games. I don't really see the point of it except to test trust. Why be in a relationship with someone you don't trust though? One of my exes did something like this. She was really unclear about her intentions, asked me a few questions that were a bit personal or that were a bit touchy, and then when I answered she clammed up. Lost respect instantly, it went downhill from there. INFP 4w5 sp/sx without much self confidence...
There are other dealbreakers, but the other SP guys covered them pretty well. They are pretty basic relationship dealbreakers.