If you ask Azurekingfisher (Flickr), what is his favourite LEGO piece, the answer will certainly be the plant leaves 6 x 5 (ref 2417 on Bricklink), as it is included in all his creations... and in great style.

They are real works of art, resulting from the symmetries of elements and colours, that result in an amazing effect, leaving everyone with their mouths open. His most recent work is intitled “Spread Wings", which seems to resemble a mythological phoenix with wide open wings and tail, with those parts made exclusively with the leaves 2417 element.
I boast his patience to place all those LEGO parts, and to give them the right torsion to create this spectacular effect.

It's well worth checking out the rest of Azurekingfisher's Flickr gallery to see other fantastic creations made by him.