Oh man.... to be honest...I cannot make up my mind as to "one" favorite caliber. I guess it depends on the circumstances...be it a long term survival situation, a hunting trip...and then what game one is hunting, and finally....economics. Bottom line I have three favorites. a 58, a 45, and a 36 cal. IF....I had to choose, no ifs ands or buts...I think i would pick the .45. Why? Well....big enough for deer, small enough for small game, and...plenty for two legged critturs if it came to that.