Since we are happily ignoring pangloss's intent here and chirping in with explanations, here are my thoughts:
1-Sig P250sc
Great idea, poorly executed. They feel great in the hand, the trigger is a DA dream, and modularity is a great thing...but it's D/Ced, SIG never really got the finished product where it needed to be in terms of reliability or features (eg, the rear sight), and it is singular enough that there will be essentially no aftermarket support for it, especially since SIG themselves won't even support it. So close, yet so far...
2-Sig P229
Classic and still very valid. Heavy and biggish for what it is, and I find it to be surprisingly thick as a carry gun, but I've had a bunch of them over the years and they have all run great. Heaps and heaps of aftermarket support in every way, plus SIG still supports them. Though SIG is certainly an imperfect friend these days for QC, their support department seems quite solid (maybe because they get so much practice?). Remember too that the controls are backwards from most everything else, which is something to consider if you train to be very thorough in decocking every time you come off the sights, and then move back and forth between gun designs. Interestingly, if you use Ernest Langdon's technique of sweeping back to decock with the left thumb, a la Beretta 92, I find that it works equally well for both and the training carries over smoothly. A good choice if it works well for you.
3-Sig P220
On paper it looks great for a full size .45, but in practice it can be a let-down. As noted, the agencies that have used them often reported very mixed results. Dimensionally similar to a 1911, so it's nice and slim to carry despite being big. I have found them to be fussy about magazines, like a not-so-great 1911. Same as above for the control locations.
4-Beretta Px4cc
It's an innovative design that works pretty well, but can be somewhat unforgiving. If you are really thorough about your maintenance, they are usually very reliable. If not, there are known issues. My hand does not fit the control levers well, so I find them to be awkward and difficult to manipulate quickly and smoothly. On the plus side, the action is very smooth, they feel great in the hand, and the DA trigger pull can be quite nice. They also feel much smaller than they look.
5-HK 2000 LEM
There are a lot of reasons why some Very Smart People like the LEM. I am not a VSP, but I like it a lot, too. It makes tremendous sense on a carry gun, even though it's not as much fun to shoot at the range. Personally, I think the P2000 is an under-rated (but maybe over-priced) design. I'm a big USP compact fan, and the P2000 is essentially a slightly improved version of that, being a bit more streamlined for carry, with a semi-configurable grip, real accessory rail, etc. Like pretty much anything made by HK, they are ridiculously durable and reliable.
6-HK 2000 V3
If you like DA/SA, everything said after the LEM part applies here. Personally, I am not particularly fond of HK's rear button decocker, as I find it less intuitive than SIG or Beretta designs. The exception is the P30 series, where I sweep the safety up and then swing around to the decocker in one motion. Otherwise, absent a manual safety, I would prefer to stick with the "Langdon left hand sweep", which isn't as natural or smooth with the rear button.
7-Walther P99AS
We're gonna party like it's 1999! It's OK, but there is really nothing to recommend it over other designs. I also don't like the idea of an 8mm trigger travel combined with a 4.5lb trigger as an initial trigger, so if I had to carry one, I would get very, very consistent about using the decock button every time I came off the sights. Limited aftermarket support, but the build quality seems good.
8-Other, including discontinued
Beretta 92 Compact. Yes, it's not very compact, but with Mec-Gar coming out with 15 round magazines, it's very comparable to the SIG P229, except with a great Beretta DA trigger, longer sight radius, and (if you want it) the option for a manual safety. Rail or no rail, you can have it either way. For some reason, the 92 Compacts from the Italian-made 2015 batch seem to have especially good triggers, even by Beretta standards. Similarly, from the discontinued list, a 92D Centurion is a great old school DAO carry gun. Langdon thin grips make either one feel much smaller and more lithe in the hand. Disclaimer: I'm very much a DAO fanboy.
HK45 Compact. If you are looking for a .45, this is a very viable option. You can get it in DA/SA or LEM, it's durable, reliable, and most people make gear and accessories for it (lights being a glaring exception, no pun intended). It weighs less than a P220, but shoots softer in my experience.