</font><font color="blue" class="small">( Why would you feel expansion is not needed? The full energy of the round will not be excerted on the target if it passes through without expansion. The best way for the energy to be transfered, is for the bullet to remain inside the target. Therefore, if the bullet expands more force is excerted and it is less likely to exit. Is't that correct? )</font>
No argument that the full energy of the round will not be transferred. But I have never felt energy was a good measure of killing power. If it was, a .22-250 would be slightly better than a .45-70 in stopping power. Or, in pistol cartridges, compare a .221 Reminton Fireball soft point vs. a 1250 fps .44 Mag solid. Both have about the same energy. The .221 will expand nicely and stop inside almost anything you shoot it at--the .44 will go through about anything you shoot it at.
Back on topic, I guess the term 'favorite' can mean different things. I answered the question earlier based on number of rounds consumed and by that measure, my favorite is the .22LR. Looking at it a different way would be to answer the question, "If you can only have one handgun, what caliber would it be?" To answer that one, I would have to say .44 Mag. It can be loaded down to popgun levels if need be, and a 1250 fps SWC load is as hot of a load as I'd ever need. Favorite gun for that load would be a 4" M29 S&W.