OK. Since we are already dating that establishes that she meets my physical standards of attractiveness and that I meet hers.
This eliminates things such as smoking or not taking care of herself/not being in shape
So assuming we are on the first date and I find out something, what would be a deal breaker for me:
Not a Christian. Obviously we can't be unequally yoked.
Liberal (democrat). Normally democrats profess/support ideas which I see as blatantly anti-scriptural. So much so that it's hard for me to even consider them Christian.
Rude to the waiter or anyone else. I try to be well mannered where ever I am and going through life being embarrassed by your wife is no way to live.
Willfully ignorant. That is, she has no desire to learn and would rather coast through life as she is. I'm far too intelligent (and humble

) to deal well with someone who would bore me to tears in just a few dates.
Lying. Do not lie to me. (ONLY allowable exception is during the planning of a surprise party of some sort. And even then a question can be avoided or deflected without lying)
Politically correct. Political correctness by another name is lying. I try to be honest and expect her to be also. Saying something just to get along is the same as lying. Either speak the truth or shut up.
Assuming we are on later dates:
(all the above plus)
Infidelity. Physical or emotional is all the same. Don't cheat on me.
Insurmountable doctrinal disagreements. For example. I believe in free will. If she is a die hard Calvinist we'll never be able to mesh completely as one. Some doctrinal disagreements are trivial, some are critical. This would be a case by case judgement.
Lack of self control. Having fun is one thing but being terminally out of control is like being rude. It's just embarrassing
Feminist. I see most of the feminist platform as blatantly anti-scriptural. (Please note that I define feminist as it is commonly practiced today, not as it was back in the 30's etc)
Complainer or generally negative. I'm almost always positive.
Manipulative or complains about me being "controlling". I am not controlling so any complaint along those lines seesk to manipulate me into doing what she wants. She'd have better success just asking. I recognize that I can only control myself (and sometimes my daughter). If she sees me as being ocntrolling then she's not ready to be in a relationship where each gives 100%
(I'm sure there's more but I can't think of them right now)