Here are my favorites in order of favorite to least favorite:
1. .357 Magnum. Simply Awesome. Nothing beats it in my mind.
2. .45 ACP. A 230 grain lumbering cannonball. I don't worry about over-penetration or failure to expand. It drills one LARGE hole.
3. .327 Federal. Hate it all you want, but this little scrapper of a round is NASTY. Shoot one, you'll like it.
4. 10mm. A super-hot .357 in an automatic with an 10+1 capacity. Ouch.
5. .44 Special. Under-rated round.
6. 9mm. Not sexy but respectable firepower in a high cap gun.
7. .40 S&W. Come on, this IS a successful round guys.
8. .38 Special. A snubbie has saved many a life. Very fun to target shoot with
9. .44 Magnum. To me, this is still the most powerful handgun in the world and always will be. Ask me to explain if you dare
10. .357 Sig. Power in the most reliable auto cartridge made. Its necked-down design allows it to enter a chamber as easy as you can enter an excited....err...will leave it at that.
Anyway, just my opinions! Would love to hear some others!