Guess I should add nothing illegal (even if their illegal practice is something I'm fine with personally, I just have enough problems as it is without begging for more through a habit of breaking the law, especially if it involves prohibited drugs which is like an obsession for many law enforcers). That definitely includes abuse and stalking (which can also fall under smothering and unjustly rude taken to an extreme), track marks, and the like.
Perhaps it's also worth noting that while I'm easygoing, I'm well aware I alienate many. Which means that they'd have to be fairly easygoing themselves (though they can have odd and even extreme beliefs as long as they also have a sense of humor about it and don't demand I become a cog in the machine of their pet cause or religion), and not many people are.
Still, I've never had to go to bars and clubs or post ads or profiles to get dates, people pursue me all the time, even when they shouldn't, and some of them have a good idea what I'm like. I was in a close relationship with a girlfriend for 5 years before the one I'm in now (and knew her for 2-3 years before that, so she knew what she was getting into), and after we broke up many who knew me were trying to snatch me up almost immediately. So I don't really care that a great many people couldn't stand me, though my other non-dating interests (and, until recently anyway, my low sex drive) also helped me to not care. (For that matter, there's plenty of people I wouldn't personally date but can still like them and wish them well, and might even be tempted to match them with someone else.)
Interesting enough, every partner (and I'm including the guys I dated in my youth) I've ever had has been very different from everyone else I ever dated seriously. That is, I don't have a type. If anything, when I wind up with someone new, I want it to be an experience I haven't had before rather than being attracted to a certain kind of person.