I carry a Keltec P-11. I wear cargo shorts almost year round and it'll fit in a pocket or IWB with a shirt untucked.
Also has last round hold open unlike the PF-9, and ten in the mag.
Glock 27 is my choice, I'm 220lbs and can conceal easy with a IWB, or a Fobus paddle holster. My wife had a Taurus TCP that fit nicely in the belt pouch. I would've kept that, but was pink...
1. How will you be dressed. It dictates what can be covered.
2. Consider the firearm and the holster (if used). TOTAL thickness and length must be considered.
3. How are you shaped? Will your body make the gun stick out. Does "dunlap" preclude belt-line carry?
4. Are you female (other consideration)?
5. Carry the the most bang you can conceal. .25 and old .32 are crap. 32 HR Mag okay in a pinch. I like .22 over .380 for vel and cap.
So many carry options:
To name a few Semiautos:
Springfield XDs (carry with pocket holster)
Sig P238 (carry with pocket holster)
Taurus PT111 or 140 or 145 (carry in concealment sweatshirt)
North American Arms 22 Mag - carry in pocket
Or Revolvers;
5 shot snub nosed - I prefer the ones with hammers so I can shoot single action
A lot depends on what you are wearing as to what you can conceal and how much weight you are willing to carry.
I was comparing the Glock 27 and CM 40 yesterday. They both feel great and the CM 40 is very concealable. I think I like the feel of the Glock better but to each his own.
I carry the XDS in a crossbreed minituck at 4:00 strong side with a LCP in the left rear pocket.
2 of the most comfortable options I have found.
The shield is about the same size, width, and weight of the XDS but in 9mm instead of 45 ACP.
45 in the XDS is BA