My vote goes to signature #3, Haruka.
Reason for chosing hers is actually pretty simple. I was amazed by the simplicity of the signature, and even though it's really pretty simple it's, atleast for me very outstanding. The background of the signature is very well chosen, since I always considered green as some nature and relaxing color, I love how she made it look like it's sparkling, not too clicheish, not too little, but enough to make you go like "Wow, this is really pretty, well done". The font is in my opinion fitting really well to image also, it's simple, yet beautiful. And then pandas are just soo cute, the yawning one made me smile infront of computer xD.
Creativity: 4
Technical: 4
Execution: 5
Aesthetic: 5
Total Points: 18
Well done (:!