All these selections are outstanding, I feel like you guys have really found your target audience and what people really enjoy about their avatars and Gaia.
I might avoid things like pointing to television shows and individual movie series, because you may alienate someone who hates those things, and attract only the people who like them. It also starts to build stereotypes about the people INSIDE Gaia. It's not as if we all enjoy Twilight and Harry Potter and talk about them all day long, and making a direct reference to it when they JOIN the site, may give them the wrong impression.
That said, this advertising is DEFINITELY a step in the right direction. I'd be proud to see just about any of these on the first page. Much better than that "be the real you" that looks like a mini-portrait of yourself. You've captured how I feel when I dress up, like I'm being somebody else. The internet cosplay XD