The gun you want is simply the gun you feel comfortable shooting and hitting something with. Doesn't matter if its a .22LR revolver, or a Desert Eagle .50AE... as long as YOU can hit something with it quickly, consistently, and accurately.
If you want a gun as a CCW that you can put on your person or in your car, you'll need something small and slender enough to WANT to carry conveneiently. If its not conveneient, you won't carry it, I promise you. A .380 in your pocket is worth a hell of a lot more than a .44 mag sitting at home.
Take those to factors into consideration, and then buy what YOU want; enjoy your shooting.
Agreeable info, but quite off topic isn't it?