This is a variation on the old "what one gun" question.If you could afford ANYTHING bar none, what’s your ULTIMATE concealed carry handgun?
Must not require NFA tax stamp.
Needs to be something actually made. Fantasy guns are pointless. Forget your Steyr GB in 10mm. Nobody makes a 11 caliber Webley Electric, with a 100 round magazine of steel needles it shoots at 10K FPS in single shot, 3 shot burst and continuous. Forget it.
The answer's going to depend on the answerer.
I would go with a variation of what I'm carrying right now. Ruger LCR or LCRx, 3", .9mm or .357 Magnum. Fit it with a Crimson Trace lasergrip, red or green, whatever. Fit it with a combo green fiber optic and tritium front sight.
It's realistic, and realistically carryable. Folks actually make good holsters for it. They actually make speedloaders for it.