A Barrett semi-auto in .50 BMG, a 12 ga with 8 rds, a 7.62 X 39 with >10rds. or a .223 carbine with several 30 rd mags would make me feel safe. The foregoing usually being impractical, my usual carry gun is a 9X19mm with .38 snub as BUG or a 9X18 Mak for carry in the pocket of cargo pants when I'm not wearing a cover garment. Large frame revolvers have adequate power but are hard to conceal. If I could, I would go armed like Josey Wales, or Mad Max when he unloads a boatload of guns upon entering Thunderdome, but chronic back pain limits how much weight I can carry.
Edit-afterthought. Emotion overcoming reason I like my E. German Mak so much that I don't feel queasy with it. It works EVERY time and I can hit what I shoot at with it. 1911 Bubba's narrative is informative, but note that the .380 DID put the BG on the trailer, and legal considerations aside he could have been shot some more with a mag change. "He fell to the ground and then got up cussing. He was bending over and holding his gut, but he got up!" The average peon (as opposed to a cop) could escape or if necessary, or shoot him in the head while he's cussing and getting up. The police are tasked with taking the miscreant alive if possible for processing by the legal industry. The threatened peon is only responsible for staying alive and unharmed. This is not to suggest that .380 is the caliber of choice, but the BG did fall down and did die later, thus preventing him from harming the minions of the law and saving the taxpayers the costs involved with his legal defense.