Like many others, my carry weapon depends on the clothing I'm wearing, the circumstances I anticipate encountering, and (sometimes) the mood I happen to be in.
Most often for me it is either a Glock 26 or a Glock 33, though I carry a Smith Mod 637 almost as often. Delta's comments about comfort are very true indeed. The weapon you leave at home because it is too heavy or uncomfortable is the one you won't have if you need it.