Chlorophyll is certainly a clever selection for favorite molecule. I imagine a more common choice among humans would be water, but what good is water alone without chlorophyll to aid in the production of fodder for consumers?
If plants, then, were asked the same question, what would their favorite molecule be? Would they also choose water? Perhaps carbon dioxide? Even hemoglobin?
Nature is so intricately interwoven that everything depends on everything else.
Thank you kindly for this food for thought!