Well.. intersting here, since I have probably shot more ammunition that all other members here combined, I can give you my opinion.
Much depend on the size and strength of your hands. If you have smaller hands HKs are defintinatly not your guns, if you have larger hands I find that Sig 239s are uncomfortable.
Stength of wrist- goes into the seletion of the caliber of the weapon, those with weak wrists cant get follow up shots on .45 cal and those larger that .357.
Ok so funtionality, you want to carry it and have it at the house, or just carry it?
Personally there are many people that will argue calibers here. I must say that I have seen every caliber popular argued more over than the whole religion debate. Here are the most popular for what you are talking about.
.380 Smaller caliber. Can be very danderous with the correct type of ammunition
.38/.357 Popular revolver ammuntion. I do not like revolvers for first time shooters. I will outlay some of the facts below.
9mm The general purpose ammunition for most weapons. People have argued that these do not have a lot of stopping power and tend to underpenetrate. I disagree as I have personally seen what a good 9mm can do. He a advantage is the magazine capacity (Dont call them clips- as that is what goes in womens hair)
.357 Sig I love this round as it is a .357 projectile that is being pushed by a necked down .40cal casing. Imaginge a .357 round flying at the speed of a 9mm +p
.40 cal one of the most popular rounds to date-98% one stop shot percentage with Federal Hydrashock ammunition. Now you also have to note that this percenatge is baseed on LE and Military incidents-not by consumers and this does matter- Will expand below.
.45 caliber made poular by the 1911s and widely used in WWII and vietnam. One reliable round that kicks like a mule and is deafening.
Ok so now to expand. Most civilaian gun exhanges occur in sistances less than 3 meters. Also there tend to be about 7-14 rounds expended per incident. Of these round only about 10% of the rounds find there mark. ( one of the reasons that I do not revolvers for first timers)
I dont care how much time that you spend in the range shooting at a target. You have what I call the pucker factor. In a live stuation with return fire your a-hole will pucker so tight that you cant drive a nail in with a sledge hammer. It is the most adrenaline rushing experience that you will ever have and I have seen trained soldiers do some god awful weird shooting once the lead satrs flying.
Now for different firarms
Kahr - good suns, I dont use them as they havent been around long enough- why trust you or your families life to a gun that has not had that many laps around the block
Glock- cobat tupperware as I call it- these things are industructable- You can leave them in the water for dasy in mud and pull them pout and fire them. Can be dropped from 15 feet high and picked up and fired, can be heates and frozenand still work. NO EXTERIOR safety is actually abonus when that pucker factor comes into play.
Beretta- Once a great gun and thenhad to produce quickly to keep up with the military acquiring them. There is a 12% failure rate in the military weapons, but they are used far more and harder that a civilian will use them.
H and K - Indestuctable as well, many of the SF uyse these guns Seals use the SOCOM, us SF Marines could use them, but mostly, we chose other weapons as these are bulky. These are great guns for primarly unconcealed weapons such as LE.
Sig Sauer- My favorite here the cadillac of guns. These were what most of my team carried in the Marines. These are undestrucable and tons more accurate than another guns due to the fact the slide is on a full length guide. These are more expensive as well.
For kicks the following:
Kimber - great 1911 variants that are highly reliable and great guns. If you do get one of these get the .40 cal
For first timers and general combat situations, I stay away from .45s. Firstly these guns are loud and if you fire and someone falls the next thing you are going to watnt to do is take cover and listen, which is hard to do with some ringing ears. At night these things throw some tremendous flaes as well from the barrel.
So in summary look for the following
Glock 26, 27
HK USP 9 Compact
Kimber ultra carry pro in .40cal
Sig Sauer 239, 228, maybe a thin 226.
Whatever you choose, practice, practice, practice. One handed, lying down, ducking, weakahded, patch over strong eye, with glasses, witout glasses, with hearing protections, without hearing protection, behind cover, shooting from around your belly button (To get shot off quicker), no light, bright light, flashing light. The more that you dont have to think the better, trust me.
Seg..
Semper Fi