You guys have beautiful knives and take some great pictures of them.
I have a few that would be very similar as far as most comfortable. I really like this knife, its the one in the middle, chances are its the one Ill have on my belt when I need to carry a fix blade.
The long one is a fine knife in the hand too. The bottom head knife was a custom order for leather work. Its much smaller than the traditional head knife or round knife. All of these where made by my friend Tony Bell.
I get alot of use out of this neck knife, it's small, total lenght about 5 1/2" but it fits and holds an edge like the fine tool steel it is. Another buddy made this one, Edgar Chattin, I've got a long hunter and a tomahawk made by Edgar too.
As far as folding knives go I carry a Victorinox Swiss Army knife all the time but a pocket knife I carry occasionally that is much more comfortable to use is the simple medium sized Opinel.
Stock photo,
This is a very inexpensive pocket knife, it is not going to impress anyone but the steel is very good and thick enough to do the job at hand, the simple locking mechanism is functional. One of my favorite all time pocket knives.