Well I am quite sociable, I have many friends, but its hard to convey it in something as formal as an interview. Interviews usually are scripted beasts and its hard to show your personality. You're stuck answering questions about teamwork, leadership, and technical stuff, not exactly a good way to show your personality. Usually, I try to get the interviewer to laugh. I'll make jokes about their age, their balding hair, or anything else I can get away with. Sometimes it works, sometimes.. it doesn't.
I did have a girlfriend for a few months in high school but she was the one that asked me so I have no experience with this whole girlfriend search.