Hm...I wonder if I'm about to regret saying this, but here we go. My 'problem' with "Fake Geek Girls" isn't that they're being fake, or that they're pretty (seriously, pretty is always a win for me). It's that I get excited about talking to them, but as soon as I start asking them questions--What did you think of the story? How'd you get past this part? Are you excited about this?--I start getting blank stares and general answers that are used to cover up the fact that they don't know, when a minute earlier they were acting like they understood. So I get a little depressed because I was looking forward to having a conversation about something that I really like talking about. Now, if the girl admits that she doesn't know that much about whatever (game, comic, book, universe) but still enjoys it, I'm fine with that. And if she wants to learn more about it, I'm perfectly happy to show her around. I just don't like getting my hopes up about talking about Star Wars or Mass Effect in detail, only to find out that the person, be it girl or guy, doesn't have the depth of knowledge I was lead to believe they had. Does that make sense?
Anyway, on to Supergirl. I've always liked her more than Superman. Heck, I've always liked ALL the younger heroes more than their mentors. The reason being exactly what Bob said: They're allowed to screw up, to change, to DIE--as tragic as that is. The originals can die, but they always come back (or never died in the first place). They always come out on top, they always overcome whatever is thrown at them. Cool to watch and read, but after a while it's no longer thrilling. It's not like that with the younger heroes. As Bob said, Supergirl acts like a teenager instead of the straight arrow Superman is, and it's that reason that I enjoyed her being one of the main characters in Justice League Unlimited and was sad to see her go. Same with when she briefly joined the Teen Titans. I like my heroes to be flawed and at risk of actual death (good-bye Kid Devil) instead of what Batman, Superman, and Wonder Woman go through.
On a side note, I just bought the Supergirl Kotobukiya statue. Very excited about that.