It is more specifically a human attribute then to have favorites that we want to share. I've written here previously admitting how I am a complete patsy for pink evening primrose (Oenothera speciosa) and winecup (Callirhoe involucrata) both.
I think I may have discovered a new favorite. Allow me to introduce you to Agapostemon, (probably A. Splendens) aka the metallic green sweat bee. I think she is absolutely breathtaking, especially in the context of her chosen backdrop.