I LOVE this image and it’s a very interesting project - Rick's peas. i would nominate this.

Thanks for the nomination. In a way, the Green Peas should be the AUTOMATIC choice: surely a picture that reflects what
Citizen Science can do- discover a new class of galaxies! This montage showing 80 Green Peas begins to try and show
what an accomplishment it was; something that only Galaxy Zoo could have done, as it involved so many people's work
distilled down to those 80 Extremely Starforming Peas. Awesome!
On the other hand, the original Mergers picture is a one-off and reflects the enormity of the Mergers thread and the
vastness of the two recent Mergers papers that have ben accepted by the MNRAS for publication. It is a fluid picture,
but as it failed to be APOD when it was last submitted, I really can't say.