Favorite format? Hands-down full size, all steel 1911, Colt Series 80. I thought it was an easy gun to shoot well, which made it a good carry gun. I had infinite trust in the safeties on that gun: grip, thumb, firing pin. I don't carry anything that large anymore, so I don't own one. My Glock 21 Gen4 is my favorite of my current collection. It is a nightstand gun.