1- First and foremost, a man who truly professes the Catholic Faith: This is a man who will most likely know beforehand what is expected of him in Marriage and most importantly, will carry on his duties and responsibilities steadily, until the very end. He will not divorce or limit his family size. He will avoid all evil in his life, such as occasions of sin, and also assure that his family attends Mass and practice the Faith, he will practice conjugal chastity and fidelity, etc. All this he will do out of deep religious convictions and sincere love for God.
2- A man with a strong work ethic. This is a man who is able to hold a job, and wake up every day in the morning to go work hard to provide well for his family. This is a diligent man who gets things done, as opposed to a lazy child-man who wants do nothing but playing video games all day, and expect his wife to work. This man is usually ambitious (in a good way) and has the stamina to carry on with his goals and gets his projects accomplished. This man is a doer, instead of a dreamer. Also, he needs to be generous with his resources, and not stingy. Stinginess in men is a red-flag and a deal-breaker.
3- A man to look up to. This man is strong. He will not melt down when problems arise, but all the family can cling to him for guidance and support. He will not be a drama queen or emotionally unstable. He will not exhibit effeminate behaviors such as complaining and blaming others for his failures. He will not be a coward, but have the ability and desire to sacrifice for the good of his family. This man solves problems. Men who women sincerely admire, are able to exert their authority over them much easily, not having to recourse to any type of harshness.
4- A man who does not have addictions. (I probably should have put this one in the top). Addictions are univocal signs of weakness of character, at the very least. There are addictions which are also signs of perversions and deep spiritual disturbances. You don't want a man who is addicted to drugs, alcohol, pornography, gambling, cigarettes, etc. Addictions are emasculating and a terrible example for your children.
Other traits that I consider good, although not necessary, are knowing how to fix and build things. It is great when a man knows how to fix things around the house or perform car maintenance (it's even better when you don't have to remind him of doing so, but he does it on his own!). Also, having a good sense of humor. It makes it for a very enjoyable company when a man makes you laugh.