I carry a full-size 17 in the winter, and a 27 subcompact .40 almost every day. They are small, but easy to conceal, utterly reliable, and accurate enough. I just saddled up a Crimson Trace laser grip on my 27 and it makes it that much more user-friendly. If I had to choose just one, I'd go with a compact like the 19. they fit larger hands better, and are easier to shoot well.