SIG pistols are awesome, though the early German-made ones are much cleaner.
GLOCKs simply work. Ugly and utilitarain, but they go "bang" every time no matter what.
Beretta pistols are generally oversized and overpriced for what they do, IMO. Nothing against their quality, on the other hand.
Smith & Wesson has great revolvers, but Rugers do the same thing for less $$. Their M&P series is a winner but really not that different from Glock or the Springfield XD. Their Sigma series is sort of a turd, but a turd that works pretty good for the money, if you can get past the trigger pull.
Colt's recent showings have not impressed me at all... and what I've heard about their manufacturing process (farmed-out parts making, ancient machinery and Mosin-refurb style parts fitting) leaves me leery. Plus, "series 80." Who needs it??
Springfield Armory won my vote. Their base-model 1911s are the best value for a quliaty .45, and their upper-end versions are practically as good as Kimber's. Not to mention they're still Series 70-style, which even Kimber has gone away from. And the Springfield Armory XD, while still not a beauty queen, looks better to me than the Glocks (not as sharp as the M&P, though), and work at least as well. Also the XDs have loaded chamber and cocked indicators that you can feel with your hands and the grip angle is "normal" compared to the Glock. PLUS, you get the gun and two mags and a holster and a mag carrier for less money than you can get a Glock and two mags.
Oh, and if you haven't shot the new EMP 9mm 1911, do it. What a sweet little CCW!!
My vote for S&W is for their M&P pistol. I have found it to be far superior to the Glock in almost every way. In fact, I once owned eleven Glocks - now I own five M&Ps and one Glock. Runner up is the Beretta 92/96: excellent pistols with most ergonomic (non-adjustable) grip on the market. I have fired H&K and SIG pistols extensively and while I will admit the latter have many excellent features, IMHO the former are usually too bulkly and have poor triggers.
Whether you want the best, most compact, safe, reliable and accurate CCW out there (P7M8), or if you want a tremendously rugged, accurate, flexible (lots of variable control set ups) and reliable polymer frame combat pistol (USP), or if you want something with high ergonomics that is adjustable, reliable and also accurate (P2000 ands soon the P30), HK is the way to go. Many of the most elite units the world over, and here in the US, carry HK sidearms (or wish they could).