The best handgun is the one in the caliber you can best hit your target repeatedly.

I enjoy and shoot alot of handguns so I will voice my opinions and hope not to offend others.

1911's are great if they are extensively reworked but most suffer from reliability issues if run hard.The best most reliable stock guns for defensive work are Glocks,Sigs,and HK's. I like HK compacts with their safety features. They are not common familiar guns. A perp who gets your gun may require some extra time to get one running.

Attacking perps require multiple hits and thus a 45 is harder to control effectively. One bullet may not get it done. You should shoot till the perp is not a threat. I have several 1911's but I personally prefer the 40 S&W in one of the guns mentioned. A 40 will also have higher magazine capacity than 1911's. When carrying a small pocket size auto a 9mm micro Kahr works nicely.

Carry a gun everyday and shoot regularly.You may form the same opinions.Its a highly personal issue and you are betting your life on your choice.Shooting defensive handguns is just plain fun.