There aren't many personality traits that I would consider to be uniquely masculine. In fact, I can't really think of any at all. Any descriptive word that could be considered a personality trait could belong to either a man or woman.
Having said that, there are certain traits I like my men to have because it makes them seem more masculine to me. (Of course, some of these same traits might be desirable in a woman from a straight mans POV because it makes them seem more feminine... )
Confident.
Honest.
Able to express emotions.
Assertive.
Positive attitude.
Intelligent.
Funny.
Social.
Hard-working.
Able to take control when necessary.
Like Laidey, I find a man more or less attractive the more I get to know him. When I first saw my current boyfriend for the first time, I thought, "Hey, he's kinda cute." Now when I see him, he appears to me like a Greek God and I swear I can hear angels singing... He looks exactly the same as he did when we met. :tongue: I typically like guys that are taller than me by at least a couple inches (I'm 5'8"), dark hair, and I love body hair as well. I've never turned a guy down for not having body hair but if I had my choice, I'd pick a furry guy any day. I'm not overly concerned with body type, really. My current boyfriend is 6'2" and weighs about 250lbs, but I've dated guys that weighed up to 330lbs. As long as I find you attractive, that's what matters. And like Laidey said, that's something that's unique to each person really. You don't have to fit certain criteria for me to find you attractive. Big hands are nice as well, I enjoy them. I think that's partly because I have big hands myself.
If you're curious, this is what attracted me to my boyfriend. He has an incredible laugh. His smile melts me. He has a super sexy mop of dark curly hair that I could run my fingers through all day long. He's super easy to talk to and is open to talking about anything. He's absolutely hysterical and never fails to make me laugh, sometimes so hard that I can barely breathe. He always says the right thing at the right time. He actually listens to me when I speak. He texts with proper grammar. I know that sounds stupid, but I really fucking hate "text speak". In the first few days of knowing him, these were the things I noticed the most.