Jim, I think that "what excites you currently" is an easier question to answer. There are so many that it's difficult to nail one down as THE favourite.
Currently, I'm building Andrew Verner's fancy rifle RCA 63. I know there are a lot of you who do not like to build copies of other's rifles and guns, but I hope you'll cut me some slack. Until very recently, I had never seen or held an original longrifle, so studying them in texts was all I had. I have found that the best way to study a rifle from a two dimensional page, is to recreate it. And the many talented builders on this site keep me accountable, so I do my very best to capture the nuances and details that make the piece so special.
Verner's work, and especially #63, really grabs me. This is the second attempt at this particular rifle, so you can see that it is important to me. I feel that the original lies in the "Golden Age", and with it's unique inlays, carving and wire inlay, is very much worth emulating. The stock architecture with the very long thin forearm and wrist have great appeal to me. And I'm a shooter - this rifle handles wonderfully.
Just last week, I finished making and inlaying the patch box, so apart from the wire inlay, all the inlay work is done. Now comes the incised carving and the wire inlay. I'll post pictures when it's done, for your critique and comments.
Then there's William Antes......