Even though they're still plenty lethal to an unarmored target, I just do not take .22's seriously. I'm incapable of it. I laugh when I see people using something chambered for .22's, and I compare the damage they do to bee stings and mosquito bites. I respect 9mm but don't really ever use it.
Really, I just don't like using anything smaller than a .40. .45 is also quite decent in my mind, as is .357, but .44 is really slightly beyond the horizon of impractical.
So my answer here is actually .40 S&W and .357 mag.
Nonetheless, this is me with a .44 magnum versus a paralyzed zombie:

That's 42 rounds aimed at the forehead from 7 meters away (39 hits, 3 misses), and then another 8 aimed at the throat from 15 meters away (5 close, 1 off-target, 2 misses).