I've grown fond of my NAA Mini Revolver in .22 Magnum. Slip it in my pocket and forget it's there. I don't have to dress around it, I can bend and turn any which way I want, and five rounds of .22 Mag that I can place with a fair amount of accuracy gives me some peace of mind.
If I feel like carrying something larger I double up to a .44 Bulldog.
"And I'm tellin' you son, well it ain't no fun, staring straight down a .44"