There isn't one you can have complete confidence in out of the box. All brands have created lemons. All of them. Complete confidence only comes with shooting and practice. As you get better with your gun, you'll come to know its capabilities just as you'll come to know your own capabilities. If it's a lemon, replace it. If not, keep it and shoot it - be confident in it.
So did you find out from your friend that this Sigma is a lemon, maybe he won't let you shoot it to know, or are you just being swayed by internet opinion? Just curious. Talk on the internet is cheap and expertise easily won. I've learned that the hard way...
Now, keeping that in mind I still have a rebut for jtduncan since he seems to think I care about this security department of his and went out of his way to call me by name to draw my attention to it... I personally know dozens of Sigma owners and none of them have had any real problems with thier Sigmas. A lot of them don't like them because they are Colt, HK, Glock, Sig Sauer, choose your brand, fans. Many of them sound just like you jt. But they still have had no problems with their Sigmas. A few of them even claimed to have had problems, but when I confronted them at the range (easy to do since I'm the PD Firearms Instructor and they have to qualify through me) thier guns seemed to work just fine. Couldn't make them malfunction. Seems to be a pattern from where I stand.
I've also done a little research since my department issues Sigmas and it is up to me to see our officers get reliable equipment. At every class I go to, I ask other instructors and officers who say the Sigma is junk how they know. None of them have been able to verify it directly - Its always "my friend said," or "I know of this department," etc. No one has actually seen it happen themselves excetp a few. After a few question to those, I find the ammunition was to fault and not the gun. So bringing up this security company again - could you e-mail me come contact information for thier firearms instructor, I'd love to learn just what was going on with thier guns...
Closest thing I've gotten is a couple instructors explained they convinced thier department to do away with the Sigma and go with a better gun. I have no problem with those guys having a preference for other guns, but the Sigma didn't have problems with those guys either.
Preference is a very important thing when choosing a handgun. If you prefer something other than a Sigma, fine. More power to you - learn to shoot it well whatever it is. But just because your preference runs differently than mine doesn't make my gun a POS. Your gonna have to prove it to me.
I'll freely accept that the Sigma may be not be as high quality as some other guns and may have more problems. Personally I won't buy any new S&W product for personal political reasons. Maybe S&W even produced a few more lemon Sigmas than can be found on average with other manufacturers, but I'm having a danged tough time tracking any of them down.
Sorry to sound as if I've been offended - I really wasn't, but I have gotten tired of blind accusations and to be singled out for my opinion demanded some rebuttal...