I would like a nice, full-size .45 or nine. I don't care if it's blue or silver. I'd just like it to be loose, grab the slide and it goes shik-fling.
For me, its all about the action. I don't give too much of a shit about the caliber arguments. The truth of it is, nobody wants to get shot, ever.
So if it's all kinds of perfect in the hand, man you're cookin' with fire.
I just love the feel of a loose gun.
I'm a lifelong shooter, former USAF security police member, and a current CCW holder.
I agree with an earlier poster who opined that concealed carry is a much better way to go unless you are deliberately doing the activism / provoking confrontation thing. The tactical advantage of the bad guy not knowing you are armed until the last instant is invaluable.
My advice to people has a ways been, keep it concealed until you decide you have no other choice than to use it, and if it comes out, it should be blazing. None of that "holding them at gunpoint" and getting drawn into standoffs and arguments / negotiations crap, that is for movies. The only way I think you would not want to start blazing away is if they IMMEDIATELY turn tail and RUN upon seeing your gun come out.
The subject of carry pistols and calibers have long been subjects of "religious wars" so don't be surprised if you get many conflicting opinions. This is just mine.... For traditional holstered concealed carry, I recommend a single stack magazine (thinner but lower capacity) 9mm semi automatic with high performance expanding slugs as the minimum. .40 S&W is a bit more powerful, but all other things about the gun being equal, will give you a little less magazine capacity. .357 Sig has vocal supporters, as it is an attempt to duplicate the stopping power of the .357 magnum (usually a revolver cartridge) ballistics in a semi-auto. The goal of matching .357 magnum performance was not quite reached, but it is still very effective for a pistol round. The magazine capacity is the same as with the .40, all other tings being equal. The .357 Sig. also has the advantage of being theoretically more reliable feeding, since it has a shouldered casing which allows the round to slide into the camber more easily. The .45 is pretty much the old reliable standby and widely acknowledged as top dog if you want to stay with the common calibers for semi-auto pistols.
Pistols have the potential disadvantage of leaving brass casings at the scene. Some cops in shootouts actually pick up there brass during real world shootouts, because that is what they always did at the range. "Civilians" have been known to do this as well. Training / practice is what you fall back under extreme stress. Another hint, when handling and loading the magazines, I recommended that you wear cotton gloves. This prevents contamination the rounds with finger oils and other contaminates.
I strongly recommend that unless you plan to put in many hours of practice, you do not use a 1911 style pistol, or any other pistol where you have to rely on a manual safety, or has an exposed hammer or a Double / single action mode. Double action only (DAO) is OK. What I personally prefer in is the Glock / springfield XD, (and others but I'm not sure) type of pistol. These pistols do not have a manual safety, they relay on a medium pressure (between a single action and a double action) trigger pull in order to fire. It won't happen by accident unless you leave you finger on the trigger guard, or some freak accident where something catches the trigger just right while holstering. They still have multiple internal safety mechanisms which would allow you to drop them or throw them and not go off. Firing these pistols is similar to a revolver (which also has no manual safety control). Just put your finger inside the trigger guard and pull the trigger.
As I see it, the main advantage of the Glock / Springfield XD type systems is that they have high ammunition capacity and as few external controls as possible to mess with at a time when you are adrenalized and your fine motor skills are greatly reduced. There are only 3 controls to deal with, and 2 of the 3 don't have to be used until the first magazine needs to be changed. Ask anyone with a firearm featuring a manual safety how often they forget to take the safety off when shooting informally. Then imagine how much easier it would be to make that mistake while fight or flight / adrenaline stress is taking place.
I used to discount the revolver as being old technology, and because they don't generally hold as many rounds as a semi auto- in some cases 1/2 to 1/3 that of a high cap 9mm. And also because they are not very flat due to the diameter of the cylinder (flat is important to make concealment easier. Also when firing a revolver the recoil tends to be sharper. But they do have the advantage of retaining the shell casings "brass" and have been traditionally been considered more reliable than revolvers. My experience has been that the Glock and Springfield XD have actually been more reliable than some of the revolvers I have fired. This may not hold true with other brands of semi-autos. Short barrel revolvers have another advantage in that I have seen special grips which have a hook like extension so the revolver can be tucked inside the waistband, and the grip es tension prevents the revolver from dropping down into your pants. Revolvers can be made pretty light, some even have titanium components. Lighter revolvers will have sharper recoil. The minimum effective caliber I would suggest for a revolver would be the .38 special with high performance expanding slugs. If you decide to go .38, increase your versatility by choosing a .357 magnum instead. The .357 will fire both .38 and .357 Magnum ammunition, and it will be more ruggedly constructed. I if you go with the .357 revolver, you can practice with the cheaper .38 special rounds and occasionally fire a few .357 just to stay familiar with the recoil. When carrying the revolver, load it with .357 ammo unless you can't shoot well with it.
Since this would be revolver for carry, get one with either concealed hammer, bobbed hammer, or shrouded hammer. You don't want the hammer catching on anything when you draw, and you never want to shoot it single action (cocking the hammer back for a lighter trigger pull) on the first shot a self defense situation anyway, unless you are trying to pick off a hostage taker. That should be left to a rifleman if at all possible.
Once you start to carry, you will likely find it a real pain in the ass. Then you will face a dilemma- to carry or not. I have decided on a compromise- a very lightweight pocket pistol, a Kel-Tec P3AT. Kel-Tec sometimes gets a bad rap for being "unreliable" but I have yet to see it. I've experienced 2 P3AT's and have friend who owns a third. All of them have functioned flawlessly. I have read on various firearms forums that Kel-Tec as great customer service and will fix you right up if you get an unreliable one. In fact all the Kel-Tec products I or my friends have ever owned have worked flawlessly. Quite a testimony for a manufacturer of such inexpensive firearms. Make no mistake, Kel-Tec firearms are ugly and utilitarian. Ruger has a knock off of the Kel-Tec called LC9. If you look at them side by side, you can see that the Ruger appears to be a total knock-off of the P3AT. The Ruger looks a tad more "refined" and has more brand name recognition. I guess imitation _is_ the sincerest form of flattery.
If you want a more refined pocket pistol, these are available as well, but they are heavier and considerably more expensive. Khar makes a very nice one, at about 4X the price. The P3AT and LC9 are double action only .380 caliber, which is basically a 9mm Short. Some believe that this is too small caliber, but it does have the huge advantage of conforming to the first rule of gunfighting- have a gun. A .45 which gets left in the night stand drawer because you don't fell like the hassle today is much less effective than the .380 "mouse gun" you actually have with you. If you go the pocket pistol route, never keep anything but the pistol in that pocket!
To learn more about pocket pistols, check out mouseguns.com
A couple final points-
ALWAYS KEEP YOUR FINGER OFF THE TRIGGER UNTIL YOU ARE READY TO SHOOT.
Treat all guns as loaded until you have personally cleared them. If you put the gun down, you should check it again (form this as a habit in case someone loaded it without you knowing it).
Never point a gun at anything you don't intend to destroy. This doesn't mean just don't deliberately point it at someone, it means don't even let the barrel sweep past someone so that it points at them even for an instant.
keep in mind what lies beyond your intended target in case you miss or get a through-and-through.
This is very important in the "gun culture."
Always ask permission to handle someone else's gun, even at a gun show.
A person handing you a firearm should "clear" it first- meaning they should check to make sure it is unloaded and hand it to you in such a way as you can easily verify that the gun is unloaded (action open and/or slide locked back, or in the case of a revolver, with the cylinder swung open. Noting exposes you as a Noob and totally clueless than poor gun handling etiquette. Gun sellers don't mind explaining the function of all the controls and demonstrating how to operate them, but they very much dislike people who have not taken the time to learn the most basic etiquette of gun handling. If you are totally inexperienced, go to an independent gun store or at least a real sporting goods store (not Wall*Mart or a pawn shop) when they are not busy. Tell them up front you don't know s about guns but are interested, and they will almost always be happy to give you a quick introduction. They love this stuff or they wouldn't be in the business.
As for actually firing guns in practice, hearing protection is a MUST. I lost some of my hearing due to shooting lots of .22s as a boy without hearing protection. Also, you need to wear safety glasses when practicing.