Buy a bagload of magazines like Combat Handguns, American Handgunner, etc. and some "buyers' guides" like The Complete Book Of Autopistols. Read what the testers have to say, that will help narrow your choices, but remember that your own opinion may be different when you've tried the guns yourself. Also remember that it's hard to find a negative review. That's partly because the mags don't review El Cheapo brands, and I suspect it may be partly reluctance to slam a product advertised in the magazine.
Based on the needs you posted, I think you should check out .40 S&Ws, .45 ACPs and .357 SIG autopsitols, or if you're into revolvers there's the .357 magnum, .41 magnum, .44 special and .45 long colt. Any one of these will stop a bad guy if the shot is competently placed. Remember that a .22 through the eye socket into the brain is more effective than a .44 magnum that misses.
The magnums and .357 SIGs are going to kick a bit and make a loud bang, but their effectiveness on target is somewhat proportional. As suggested, go to a range with rentals. Try a variety and (my personal philosophy) select the hardest-hitting caliber that you can control comfortably. Comfortable control is when you can fire deliberate shots about a second apart and keep the weapon on target.
As for a laser, they can be added in one of three ways. A pistol with an accessory rail can be fitted with a laser hanging under the muzzle, though this makes it hard to find a holster. Crimson Trace makes its LaserGrips for many guns, they don't interfere with standard holsters. Nor does the LaserMax, which replaces the guide rod on autopistols.
You don't say whether you need something for concealed carry or only for a home gun. If it's for CCW, it will help to pick something smaller; if for home only, a bigger frame will help with the recoil a bit.
You also need to consider action types. Single action, double action (with safety and/or decocker), double action only, or "safe" action (Glocks). The simplest to operate are DAOs and Glocks. Minimal number of external controls, just point and squeeze. Single actions Colt 1911s and clones) have very light triggers. This makes it easier to hold on target as you squeeze, but you need to be well trained in the manual of arms since the light trigger makes it easier for an untrained person to cause an unintended bang.
Do NOT accept it when someone tells you "Brand X is the one and only gun, all others are crap". Like with cars, brand loyalty is strong among shooters. If someone gives you a strong recommendation, you can check it out, but make sure you get what works well for you.
Hope these thoughts help, Tuff, and be sure to let us know what you selected (so we all can second-guess you and say "You shoulda bought the Combat Bozomatic 99,000.")
