Number 1 is my favorite by far. The composition with the fading into the background is unreal. Color saturation is perfect on my laptop. I completely agree with KenC, as the cropping would just add that much more to the picture.
Picture 2 has a softer feel to it that's due to the almost white pastel color of the flowers. Still, a very strong composition.
Picture 3 just isn't as strong of a composition as the other two photographs. Other then that, I really can't put my finger on it, perhaps a single flower is harder to compete with the other two photographs, especially the 1st one. To me it's strongest point is the directional lighting.