the problem with the question is when would you not worry about over penetration? maybe war time combat, but in any practical setting you need to worry about what is behind the target.
A .500, .50, .44 mag, .454, .480 will fly through an avg 6'1" male 230 pounds. I have used a .44mag deer hunting and have in and outs all the time (within 100yards)
A .45 in hollow point is less likely to go through a person but does happen, talk to a police officer they are very careful about shooting anything, for this same reason. I would but 10mm in this same area.
.40,.357sig, .38, 9mm all have very controled delivery of force and penetration.
everything above also depends on ammo type. as zampolit said hyrdoshocks are a hard hitting round. and Glasers will make almost anyone drop to a knee.
If you just want to put holes in stuff, i would say .44 or .50 would be your caliber of choice, they both come in revolver and semi auto, both are easy to find in a varity of loads and both (if shot right) will drop almost any human on the planet in one shot. If the person happens to be on PCP, a shot to the chest will blow out most of thier vital organs and then they are stopped.
But i have to admit shooting a .500 would be cool, nothing like shooting through a car antoher car and then the person and then the car behind him.
all above is personal experiance with these differant calibers and personal opinion on thier stopping power.