Why a 1911?
Some observations:
The Browning 1911 and its derivatives are fundamentally sound; nothing has come on the scene that radically improves them. In fact, virtually all modern op systems are Browning, Improved Browning, or Browning-Petter. I agree with the earlier post that CZ, Sig, H&K, and Glock have produced some evolutionary steps, but no real revolutions.
For many decades, 1911s were just about the ONLY model of semi-auto that a large portion of the American shooting public had any experience with at all. This changed during the 60s-80s; eventually, the hi-cap 9mm craze hit its peak, the US Armed Forces changed to the Beretta, and .38 Spec/+P virtually disappeared from the law enforcement scene. The powers that be (don't think this doesn't include the major domestic manufacturers) decided that foreign hi-caps had to go, so the 1911 has become popular again.
I agree that the 1911 and its derivatives are EXCELLENT pistols. Single-stack, all-steel construction, grip angle, etc. all combine to make a gun that is greater than the sum of its parts.
That said, the 1911A1 is not perfect, at least IMHO. I hate the grip safety, but this can be eliminated. The stock SA trigger of the 1911 is great, but there are stock SA triggers that are comparable or better (older BHPs and CZ 75s come to mind). A lot of the credit given to the 1911 should really go to the .45 ACP cartridge. It is very difficult to find an inaccurate pistol in this caliber.
I own two .45 semi-autos: a CZ 97B and an FEG GKK. The only thing that prevents me from owning a 1911 is the simple fact that EVERYONE I know (that shoots, of course) owns one. I am fairly certain that I will own a Colt Commander-style pistol within the next couple of years.