I was Twilight Sparkle at my local con over the weekend, together with my friend as Pinkie Pie. We had way too much fun, even though we didn't see a whole lot of other MLP cosplayers.
Princess Bubblegum (Adventure Time)
Marceline (Adventure Time)
Suiguintou (Rozen Maiden)
Twilight Sparkle (Princess - My Little Pony)
Rest to be decided.