I'm kind of partial to the 2213 S&W series myself. The low bore axis means the sights are useable without modification, the smooth slide allows you to put your thumb on the back to hold the slide closed, and the short barrel keeps most things subsonic. Easy to add a barrel nut/ thread adapter, too.
http://www.geocities.com/yosemite/tr...0/Hsw2213L.gif
from Google images