Glock 26 or P-64
Normally, i carry my Glock 26 with Remington Golden Saber 124gr. +p's in a Bianchi IWB. It's pretty comfortable and underneath an unbuttoned short sleeve shirt, completely concealed.
Occasionally i'll grab my P-64 ( Polish milsurp, resembles a PPK, 9x18mm, Hornady 95gr. XTP's ) when i need something a little narrower than my Glock.