I've yet to find a caliber I don't like to shoot. That being said I usually stick to 9mm because of price (and availability) of practice ammo.
Clearly it's not as powerful as some other rounds, but it's certainly powerful enough for it's intended purpose.
Some people are too concerned with "power". I wonder if these are the same people who drive a Dodge 2500 to commute from their condo in the 'burbs to their office. My 9mm gets the job done, just like my accord gets me to work.
As far as accuracy goes, I'm usually the weakest link in the gun-ammo-shooter chain, so I've never noticed