In order from most carried...
Keltec P32 (most of the time)
Taurus M85UL (outdoors)
Kimber Compact (winter)
I do not feel confident concealing the larger guns. The most the vests I see are usually too tactical looking. Nothing says dork like a fanny pack.
I carry the Keltec using two methods. Attached clip on on the waistband or in a Michaels pocket holster which I modified to carry an extra mag.