Here's a round-up of some favorites:
I carry either the Smith and Wesson mod 638 bodyguard .38 spcl snubby or, if in short pants/tee shirt, a KelTec P32
The Colt pocket lite or pocket 9 are nice pieces but can get a little pricey and they're both a bit on the heavy side.
The NAA guardian in .380 or .32 ACP are TRUE pocket guns with nice workmanship and excellent warranties.
The KelTec P11 in 9 mm is an amazingly small semi-auto weighing about 20 oz fully loaded with 10+1 and the P32 is my personal favorite for deep concealment. KelTec likewise, has an excellent lifetime warranty.
The Kahrs are thin and well made albeit a bit expensive. The all metal MK9 is a thing of beauty but, man, I'd get tired of toting around something that weighs about 24 oz plus ammo!
The new polymer P9 is much lighter (15 oz) but Kahr is having some teething problems with their polymer-framed models.
The Glock mod 26/27 are compact and light but feel about as wide as a 2x4 in the pocket.
Personally speaking, having toted nearly a dozen different "pocket" guns around for years, the Smith and Wesson snubbies are my favorites: the mod 342 weighs in at just over 11 oz but is very $$$$. The 642 is about 16 oz, the 638 is about 15 oz and all of these are easily-carried. For quick drawing/acquiring/firing, they're hard to beat; they're dead-reliable, and you can buy some extremely potent rounds for them.
Taurus makes several very lightweight .38 spcl snubbies, weighing as little as 13 oz (M85 total titanium)
Believe me, if you are truly dedicated to toting in the pocket 24-7, SIZE and WEIGHT do make a big difference. For my fussy tastes, anything over a pound is already getting on the heavy side.
There are lots and lots of choices out there; your task is to sort through them and decide. I'm sure you'll find something that you will be satisfied with.