large handgun calibers, Hollywood, carry...
To be honest, nearly any large handgun caliber could protect or defend you in a real use of force event.
Unlike Hollywood movies & TV shows where practical concerns like noise, muzzle blast, recoil, over-penetration, ricochets, spare magazines-tactical reloads etc are not important, to use a large caliber is a choice made after considering all the factors.
In general, I'd say the .44spl is really the largest common size I'd pick. Other large calibers like the .50GI, .50AE, .454 Casull, .44magnum, .41magnum could be useful in limited applications but not for general carry either open or concealed.