357 mag would be my vote.
I feel it is available in more kinds of fire arms than any other round. (revolvers of every size, Derringers, single shots, lever actions, bolt actions, mares legs, 1911 style Coonan, Desert Eagles to name a few)
Shot placement is everything! I would rather take a round of 50BMG to the foot than a 22short to the base of the skull.
all 25 of my guns are 45/70 govt, 357 mag, 22 or 12 ga... I believe in keeping it simple