The first one, the graphic work is outstanding. The graffiti and the colors of the girl and walls compliment each other great.

I really the second one the most, as blue is my favorite color. The fonts fit the subject too.

The third one is very well put together too, but I dislike it the most because its too bright and too much white. Not to say that its not beautiful, it is! Just too much white IMO ^^;

Anyway, great work, I'd love to see some more!