The Ruger, just for reliability and "clubbing" ability, would be hard to beat. I've had success with the G21. I'd give no credence whatsoever to the Portland PD G21 debacle. They used G21s for ten years or so, then had two explode during the same range session. One of their "firearms experts" (anybody really believe that there's a firearms expert on Portland P.D.'s payroll?) decided that the Glock design was at fault. White Labs, however, opined that bad ammo was the problem. Makes a lot more sense that it was the ammo, now, doesn't it?
I also find my 1911s to be totally reliable. Maybe I just got lucky, but I've fired thousands of rounds through my 1911s, with no failures that weren't ammo related...same with Glocks.
In a real life-or-death situation, a semi-auto doesn't have to be reliable for more than a few rounds, so must about any pistol that you've fired enough to become comfortable with will work for s.d. purposes. If, however, you're interested in the kind of reliability issues that might cause you to fail in a gun games session, then just observe what everybody else is using and what kind of problems they generally have.
