My 24-7 carry gun is a HK USPc V9 in .45
Depending on the weather and the clothing....
Kahr PM9 or my new FNP 40.
Depending on the situation:
Hog Hunting: 40 Cal USP in a Galco Concealable
Jacket Weather: Sig p239 9mm
Not jacket weather: pocket pistol of some flavor, lately Beretta Tomcat in .32 or Walther PPK. Tried the Glock 27 in this role, but it's too clunky.
Kimber Ultra Carry Stainless in a pager pal (this one went bye-bye. Very sad.)
Car gun: Sig 229 9mm with a Don Hume belt holster if needed.
Like most of the others here it depends on the clothing and situation. At work I wear a vest so I tuck a Polish p-64 or a Beretta 84 in it. When just in general public places movie, resturant, ect. my Baby Eagle. Around the house S&W Sigma. Then when I get tired of those I switch to the M&P, Taurus pt-111, or Beretta 92.
When conditions permit, I carry a .40cal P99 in a high ride Fletch by Galco, but most times, a .380 ppk/s-1 in a tuckable Don Hume.
I alternate between my HK USPc 9mm (minus the light rail, of course) and XD-9SC, both loaded with Corbon 115gr +P.
This is all I really have as far as concealability. I used to carry my S&W686 that I use for hunting. Now it is this HK USP .40. It now rides in a FOBUS paddle holster but is waiting on a new Mitch Rosen 5JR.
mostly beras t380. also s&w model 642 .38+p always kel tec .32 as BUG.
In the summer, I carry a Keltec P3AT in a front pocket.
When wearing a jacket, I carry a Kahr P40.
Carried in this: