I've shot a number of handguns....
I love the full size 1911, but like has been said, not easy to hide.
The Beretta 92 and clones are nice too (Taurus makes a good one), but if you're going to haul around something that big, you might as well carry a 1911.
Not a Glock fan. I've shot a couple and I don't really care for them - especially when it comes to carry - that only a trigger safety doesn't seem as safe as I'd care for if I had to carry one. And yes, I know that the Springfield XD is a very similar pistol.
I <3 Springfield XD pistols. Not a fan of .40 cal though (in anything), IMHO, it has too much tendancy for muzzle flip. The .45 is nice though. And better yet is Springfield's newest release - a pocket sized .45 (5 in the mag, one in the pipe) - I'm anxious to be able to try one out!
For carry revolvers, I'd go with a Taurus Total Titanium in .38 - light weight, small, good sized grip, and comfortable to shoot.
Personally, if I were to carry, I'd go with the biggest caliber I felt comfortable to shoot and that I could hide on me (in other words, I would carry a Desert Eagle .50ae if I could find a way to hide it).
As far as holsters go, I think it would depend on how you plan to carry it. The bigger the gun, the harder to hide. You have to think not only about comfortably carrying it, but also preventing it from "printing" through your shirt - IE, you don't want a big gun where if you turn wrong or something, the outline of the grip shows clearly through your shirt - kind of defeats the purpose then.