Let's get this out of the way so I don't have to constantly mention it again: I'm actually a guy, but I also dress up as a girl primarily for the lulz, thus the username Troll Princess.
That said, I humbly present myself as an avid cosplayer of sorts, better known recently at last Sakura-Con as the crossplaying Rarity in the white dress, as well as the Spy from Team Fortress 2 with Rarity's wig. Needless to say, Rarity is without question my favorite pony (I wouldn't call her "best pony", though, since I don't like playing the "best pony" game).
I also consider myself a writer of sorts; though I haven't written anything directly related to MLP so far, I have used some elements of it as a motif. Also, if anypony out there would like to suggest an idea for a one-shot or whatever, I'm always in the mood to practice.
Thanks, and have fun.