Springfield Armory for standard off-the-shelf stuff and up. Forged slide/frames, lifetime warranty, have a model to suit just about any need, one of the best costom shops in the biz.
Dan Wesson for upper range 'semi-custom' pistols. While not quite the bargains they were a few years back, you'd be hard pressed to get a better assembled 1911 at just about any price.
Wilson Combat for Top End semi-customs. He's been at it since about the beginning of our current era, top notch components, lifetime warranty, and is actually a true custom shop (will build to your spec) unless something's changed.
BOSS