What character traits in a person do you find most appealing???

If you were at a party or some other kind of social get-together (non-drug or drinking, just hanging and socializing) and you didn't really know anyone all that well, (let's say you talked to a couple of people there last week briefly, but that's the only time you had ever met them) how would you act? Would you randomly walk up to groups of people who were already engaging in conversation? Would you introduce yourself to everyone? Would you be more reserved? Would you act goofy, keep in mind that there are 20 somethings and adults here. I'm kinda shy when I first get to know people, my self confidence has gone through the ringer over the past couple of months because I've been laid off of my job, but I'm going back soon, a girl that I cared about a lot decided it would be better to just be friends, that hurt big-time. Socially, how do you guys interact? What do you talk about, how do you act in a new social environment were you want to make friends. What should you not talk about. Hlp!