If I were to cosplay, I would probably crossplay as Nepeta from Homestuck.
Or some other character from Homestuck, only the rest of my options would be guys, because as awesome as it would be to pick Jade or something, all the other girls in the comic wear freakin' skirts. Maybe John. If I got myself a wig, I already have all that would be needed for his Vriska outfit.
Nepeta, however, would be just challenging enough, and just fun enough, without being too hard to pull off. Also, I just plain dig her outfit and everything she stands for as a character.
Why so determined to crossplay? Because I enjoy going off the deep end. If I'm going to make a fool out of myself, I am going to be most foolhardy foolish fool that had ever been fooled. Publicly.
Why so determined to do Homestuck? Because none of the other things I like are easily cosplayable. Death Note is old and has been overdone, video game characters practically always require very complex/hard to design outfits, etc.
Why so detailed about these events when I'm not actually going to be cosplaying? Well, I'm not going to be cosplaying for a while, but I plan on doing it eventually, because dress-up is just plain spazztastic v_v;