I have carried a bunch of different guns over the last few years. Kahr CW9, S&W 19 2.5", XD40 service, LCP, Springfield TRP, Ruger commander 1911, Sig 226, S&W 642, S&W Shield 9mm, Glock 19, Ruger speed 6 4", Gp100 4" and 3".
Drum roll please....And the winner is.
S&W Shield 9mm carried in a comptac infidel. This combination is easy to carry in anything but PT gear. It's also fun and inexpensive to shoot which means more practice. Everyone I let shoot this gun ends up buying one.
I do carry my Glock 19 in a Fox IWB about 40% of the time. I almost never pocket carry the J frame or LCP any more. The bigger guns are easier to shoot well and I like having my pockets free for keys, wallet, phone, ect.