The gun is only half the matter. How you carry it is equally important. The consequences of a failure in concealment will determine if more or less out of sight is adequate or if you need it to be undetectable short of a thorough search. In general, the bigger the gun, the harder it is to conceal. Will you have to change your wardrobe to accommodate your gun? Comfort is also an important consideration since it will affect your willingness to carry all day every day. Depending on your answers to these questions, your options range from a Beretta 92 in a shoulder or OWB belt holster to a Keltec P32 in a pocket holster. As far as recommendations go, there are good reasons why the M&P Shield is so popular. I would also suggest looking at the Walther PPS and Kahr CW9.