Ryoken surprised me with this back in late 2007, judging by the timestamp; however, I remember receiving this before I even had a Furaffinity account. This was the first image of my dragon ever that came even remotely close to capturing how he looked. I didn't have a lot of reference material, obviously, and as a surprise, he didn't really have any opportunity to go back and forth with me on the anatomy. In spite of that, he pretty much nailed it. I've simplified his ears - only three spars - and changed the base of his horns so that they have a base more like an eland (the skin doesn't climb the horn, and doesn't really envelope it at any point anymore), and I've put a lot more thought into the biology and lifestyle of dragons (his horns, to run with it, are horn-over-bone now, and filed blunt every year or so to protect his bedding), but this is where the vision really gelled in my mind for the first time.
Also included is the thumbnail used on Ryokan's privately-hosted gallery while it operated.