There is no "best" caliber. To many variables(plinking, home defense, CCW, hunting, etc.). The key is to choose the caliber that bet fits your needs AND your ability/likeness.
For CCW, I carry a Sig 229 in 357Sig. In the woods, I carry a Glock 20 (10mm). Its what I like. Shoot as many as you can and then choose. For the reloader, the 10mm and 357 mag are hard to beat.
Just for fun, check out "caliber corner" on glocktalk. Talk about some caliber wars!